Patent Publication Number: US-2020285379-A1

Title: System for gaze interaction

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 15/379,233 filed Dec. 14, 2016, entitled “SYSTEM FOR GAZE INTERACTION,” which is a continuation-in-part of U.S. patent application Ser. No. 14/985,954 filed Dec. 31, 2015, entitled “SYSTEM FOR GAZE INTERACTION,” which is a continuation-in-part of U.S. patent application Ser. No. 13/646,299 filed Oct. 5, 2012, entitled “SYSTEM FOR GAZE INTERACTION,” which claims priority to U.S. Provisional Patent Application No. 61/583,013 filed Jan. 4, 2012, entitled “SYSTEM FOR GAZE INTERACTION,” the entire disclosures of which are hereby incorporated by reference, for all purposes, as if fully set forth herein. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention generally relates to computer implemented systems and methods for utilizing detection of eye movements for gaze driven interaction in connection with interactive graphical user interfaces, and in particular, to systems and methods for gaze interaction with portable devices. Further, the present invention relates to systems and methods for assisting a user when interacting with a graphical user interface by combining eye based input with gesture based input and gesture based user commands. 
     Human computer interaction has been revolutionized by the introduction of the graphical user interface (GUI). Thereby, an efficient means was provided for presenting information to a user with a bandwidth that immensely exceeded any prior channels. Over the years the speed at which information can be presented has increased further through color screens, enlarged displays, intelligent graphical objects (e.g. pop-up windows), window tabs, menus, toolbars, etc. During this time, however, the input devices have remained essentially unchanged, i.e. the keyboard and the pointing device (e.g. the mouse, track ball or touchpad). In recent years, handwriting devices have been introduced (e.g. in the form of a stylus or graphical pen). Nevertheless, while output bandwidth has multiplied several times, the input bandwidth has been substantially unchanged. Consequently, a severe asymmetry in the communication bandwidth in the human computer interaction has developed. 
     In order to decrease this bandwidth asymmetry as well as to improve and facilitate the user interaction, various attempts have been made to use eye-tracking for such purposes. By implementing an eye tracking device in e.g. a laptop, the interaction possibilities between the user and the different software applications run on the computer can be significantly enhanced. 
     Hence, one interesting idea for improving and facilitating the user interaction and for removing the bandwidth asymmetry is to use eye gaze tracking instead or as a complement to mouse input. Normally, the cursor is positioned on the display according to the calculated point of gaze of the user. A number of different techniques have been developed to select and activate a target object in these systems. In one example, the system activates an object upon detection that the user fixates his or her gaze at a certain object for a certain period of time. Another approach is to detect an activation of an object when the user&#39;s eye blinks. 
     However, there are problems associated with these solutions using eye tracking. For example, the humans use their eye in perceptive actions instead of controlling. Therefore, it may be stressful to carefully use eye movements to interact with a computer, for example, to activate and select an object presented on the display of the computer. It may also be difficult to control blinking or staring in order to interact with objects presented on a display. 
     Thus, there is a need within the art for improved techniques that enable user interaction with a computer provided with an eye tracking device allowing the user to control, select and activate objects and parts of objects presented on a display of the computer using his or her eyes in a more intuitive and natural way. Furthermore, there is also a need within the art for techniques that in a more efficient way takes advantage the potential of using eye tracking for improving and facilitating the user interaction with a computer. 
     One such attempt is presented in US pat. appl. (publication number 2005/0243054) to Beymer et al. in which a technology for selecting and activating a target object using a combination of eye gaze and key presses is disclosed. More specifically, a user looks at a target object, for example, a button on a graphical user interface and then presses a selection key of the keyboard. Once the selection key is pressed, a most probable target is determined using probability reasoning. The determined target object is then highlighted and the user can select it by pressing the selection key again. If the highlighted object is not the target object, the user can select another target object using additional keys to navigate to the intended target object. 
     However, this technology is limited to object selection and activation based on a combination of eye gaze and two sequential presses of one dedicated selection key. 
     In U.S. Pat. No. 6,204,828 to Amir et al., a computer-driven system for aiding a user to positioning a cursor by integrating eye gaze and manual operator input is disclosed. A gaze tracking apparatus monitors the eye orientation of the user while the user views a screen. Concurrently, the computer monitors an input device, such as a mouse, for mechanical activation by the operator. When the computer detects mechanical activation of the input device, it determined an initial cursor display position within a current gaze area. The cursor is then displayed on the screen at the initial display position and thereafter the cursor is positioned manually according to the user&#39;s handling of the input device without regard to the gaze. 
     Consequently, there still remains a need within the art of an improved technique that in a more efficient way takes advantage of the potential in using eye tracking for improving and facilitating the user interaction with a computer and in particular user interaction with graphical user interfaces. 
     Interactions with portable devices and the like have developed substantially, from the traditional computer mouse and keyboard to new modalities such as touch, gesture and gaze driven inputs. 
     Typically, these portable devices function using touch as the primary or often only input method. This presents certain issues in ergonomics as well as usability. For example, when touching a screen on a mobile telephone/tablet, part of the screen is obscured. Further it may be difficult to touch the screen while simultaneously holding the phone/tablet, therefore two hands may be needed. 
     It is an object of the present invention to provide systems and methods which provide for interaction with a portable device that is more convenient than traditional touch based input as it allows use of the majority of the display. 
     BRIEF DESCRIPTION OF THE INVENTION 
     An object of the present invention is to provide improved methods, devices and systems for assisting a user when interacting with a graphical user interface by combining gaze based input with gesture based user commands. 
     Another object of the present invention is to provide methods, devices and systems for user friendly and intuitive interaction with graphical user interfaces. 
     A particular object of the present invention is to provide systems, devices and methods that enable a user of a computer system without a traditional touch-screen to interact with graphical user interfaces in a touch-screen like manner using a combination of gaze based input and gesture based user commands. Furthermore, the present invention offers a solution for touch-screen like interaction using gaze input and gesture based input as a complement or an alternative to touch-screen interactions with a computer device having a touch-screen, such as for instance in situations where interaction with the regular touch-screen is cumbersome or ergonomically challenging. 
     Another particular object of the present invention is to provide systems, devices and methods for combined gaze and gesture based interaction with graphical user interfaces to achieve a touchscreen like environment in computer systems without a traditional touchscreen or in computer systems having a touchscreen arranged ergonomically unfavorable for the user or a touchscreen arranged such that it is more comfortable for the user to use gesture and gaze for the interaction than the touchscreen. 
     In the context of the present invention, the term “GUI” (Graphical User Interface) refers to a graphics-based user interface with pictures or images and words (including e.g. signs and figures) on a display that incorporate, for example, movable windows and icons. 
     Further, in the context of the present invention the terms “object” or “object part” refer to an interactive graphical object or GUI object such as a window, an icon, a button, a scroll bar, a hyperlink, or non-interactive objects such as an image, text or a word in a text that the user desires to select or activate. 
     In the context of the present invention, the term “touchpad” (or the term “trackpad”) refers to a surface sensor for detecting the position and movement of one or multiple fingers and/or one or multiple other objects intended for pointing, drawing or making gestures, such as for instance a stylus. 
     These and other objects of the present invention are achieved by means of a system having the features defined in the independent claims. Embodiments of the invention are characterized by the dependent claims. 
     According to an aspect of the present invention, there is provided a control module for implementation in, for example, a computer device or handheld device or a wireless transmit/receive unit (WTRU) for handling and generating gesture based control commands to execute user action based on these commands. The control module is configured to acquire user input from input means adapted to detect user generated gestures and gaze data signals from a gaze tracking module and to determine at least one user generated gesture based control command based on the user input. Further, the control module is configured to determine a gaze point area on the information presentation area including the user&#39;s gaze point based on at least the gaze data signals and to execute at least one user action manipulating a view presented on the graphical information presentation area based on the determined gaze point area and at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. The gaze point area serving as a starting point may be an area at which the user initially gazes at or a fine tuned area, i.e. an area that the user has selected by tuning or correcting commands via, for example, the input means, thereby correcting or tuning an initial gaze point area to a selected area. 
     According to another aspect of the present invention, there is provided a method for generating gesture based commands during user interaction with an information presentation area, for example, associated with or included in a computer device or handheld device, or associated with or included in a wireless transmit/receive unit (WTRU). The method comprises acquiring user input corresponding to user generated gestures and gaze data signals and determining at least one user generated gesture based control command based on the user input. Further, a gaze point area on the information presentation area including the user&#39;s gaze point is determined based on at least the gaze data signals and at least one user action manipulating a view presented on the information presentation area is executed based on the determined gaze point area and at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. 
     According to a further aspect of the present invention, there is provided a handheld portable device provided with or associated with an information presentation area and comprising input means adapted to detect user generated gestures and a gaze tracking module adapted to detect gaze data of a viewer of the information presentation area. The handheld device further comprises a control module configured to acquire user input from the input means and gaze data signals from the gaze tracking module and to determine at least one user generated gesture based control command based on the user input. The control module is further configured to determine a gaze point area on the information presentation area including the user&#39;s gaze point based on at least the gaze data signals and to execute at least one user action manipulating a view presented on the information presentation area based on the determined gaze point area and at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. In embodiments of the present invention, the handheld device may be a cellular phone, a smartphone, an iPad or similar device, a tablet, a phoblet/phablet, a laptop or similar device. 
     According to a further aspect of the present invention, there is provided a wireless transmit/receive unit, WTRU, associated with an information presentation area and comprising input means adapted to detect user generated gestures and a gaze tracking module adapted to detect gaze data of a viewer of the information presentation area. The WTRU further comprises a control module configured to acquire user input from the input means and gaze data signals from the gaze tracking module and to determine at least one user generated gesture based control command based on the user input. The control module is further configured to determine a gaze point area on the information presentation area including the user&#39;s gaze point based on at least the gaze data signals and to execute at least one user action manipulating a view presented on the information presentation area based on the determined gaze point area and at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. 
     The term “wireless transmit/receive unit (WTRU)” include but is not limited to a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a cellular telephone, a smartphone, a personal digital assistant (PDA), a computer, or any other type of device capable of operating in a wireless environment such as a wireless local area network (WLAN) or wireless mobile communication system (e.g. a third generation (3G) global system for mobile communication and systems for mobile communication including long term evolution (LTE) cells). 
     According to another aspect of the present invention, there is provided a system for user interaction with an information presentation area. The system comprises input means adapted to detect user generated gestures and a gaze tracking module adapted to detect gaze data of a viewer of the information presentation area. Further, the system includes a control module configured to acquire user input from the input means and gaze data signals from the gaze tracking module and to determine at least one user generated gesture based control command based on the user input. The control module is further configured to determine a gaze point area on the information presentation area where the user&#39;s gaze point is located based on at least the gaze data signals and to execute at least one user action manipulating a view presented on the graphical information presentation area based on the determined gaze point area and at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. 
     According to yet another aspect of the present invention, there is provided a computer device associated with an information presentation area. The computer device comprises input means adapted to detect user generated gestures and a gaze tracking module adapted to detect gaze data of a viewer of the information presentation area. The computer device further comprises a control module configured to acquire user input from input means adapted to detect user generated gestures and gaze data signals from a gaze tracking module and to determine at least one user generated gesture based control command based on the user input. Moreover, the control module is configured to determine a gaze point area on the information presentation area including the user&#39;s gaze point based on at least the gaze data signals and to execute at least one user action manipulating a view presented on the information presentation area based on the determined gaze point area and at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. 
     According to embodiments of the present invention, the computer device may, for example, be any one from the group of a personal computer, computer workstation, mainframe computer, a processor or device in a vehicle, or a handheld device such as a cell phone, smartphone or similar device, portable music player (such as e.g. an iPod), laptop computers, computer games, electronic books, an iPAD or similar device, a Tablet, a Phoblet/Phablet. 
     According to embodiments of the present invention, the input means is configured to detect user gestures by a hand or a finger (or fingers), for example, relative a keyboard or an information presentation area using, for example, an optical measurement technique or capacitive measurement technique. 
     According to an aspect of the present invention, there is provided a system for user interaction with a wearable head mounted information presentation area. The system comprises input means configured as a gyro ring adapted to detect user generated gestures and adapted to wirelessly communicate with a control module also communicatively connected to the information presentation area as well as a gaze tracking module adapted to detect gaze data of a viewer of the information presentation area. A control module configured to: acquire user input from the input means and gaze data signals from the gaze tracking module; determine at least one user generated gesture based control command based on the user input; determine a gaze point area on the information presentation area including the user&#39;s gaze point based on at least the gaze data signals; and execute at least one user action manipulating a view presented on the graphical information presentation area based on the determined gaze point area and at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. 
     According to a further aspect of the present invention, there is provided a system for user interaction with an information presentation area. The system comprises input means adapted to detect user generated gestures, wherein the input means comprising at least one touchpad arranged on a steering device of a vehicle or adapted to be integrated in a steering device of a vehicle. Further, the system comprises a gaze tracking module adapted to detect gaze data of a viewer of the information presentation area and a control module configured to: acquire user input from the input means and gaze data signals from the gaze tracking module; determine at least one user generated gesture based control command based on the user input; determine a gaze point area on the information presentation area including the user&#39;s gaze point based on at least the gaze data signals; and execute at least one user action manipulating a view presented on the graphical information presentation area based on the determined gaze point area and at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. 
     According to embodiments of the present invention, the input means includes a touchpad configured to enable a user to generate gesture based control commands. The gesture based commands can for example be generated by moving at least one finger over a surface of the touchpad or touching a surface of the touchpad with, for example, the finger. 
     According to embodiments of the present invention, a dedicated part or area of the touchpad surface is configured to receive gesture based control commands. 
     According to embodiments of the present invention, at least a first dedicated part or area of the touchpad surface is configured to receive a first set of gesture based control commands and at least a second part or area of the touchpad surface is configured to receive a second set of gesture based control commands. For example, the touchpad may be configured to receive gestures such as scrolling or zooming at a dedicated area or part. 
     In embodiments of the present invention, the control module is configured to determine at least one gesture based control command based on multiple simultaneous user input via the input means. Further, a gaze point area on the information presentation area where the user&#39;s gaze point is located is determined based on the gaze data signals and at least one user action manipulating a view presented on the graphical information presentation area is executed based on the determined gaze point area and the at least one gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. 
     According to embodiments of the present invention, an input module is configured to interpret signals representing at least one user generated gesture to provide at least one gesture based control command reflecting a user&#39;s gesture. According to embodiments of the present invention, the input module is arranged in the control module. 
     In embodiments of the present invention, the input module is configured to interpret the signals representing the at least one user generated gesture using gaze input signals and/or a predetermined set of possible gesture based control commands, each possible control command corresponding to a particular user gesture relative the input means. 
     According to embodiments of the present invention, at least one object is presented on the graphical information presentation area, the object representing at least one graphical user interface component and configured to be manipulated based on the user-generated gesture based control commands, wherein the control module is configured to determine if the gaze point of the user is on an object or in an area surrounding that object based on the gaze data signals. Further, the control module may be configured to determine if the gaze point of the user has been on an object or in an area surrounding that object at a predetermined point in time based on the gaze data signals. For example, the control module may be configured to determine if the gaze point of the user was on an object or the area surrounding that object 0.1 seconds ago. 
     User activation of the object is enabled if the user&#39;s gaze point is on or within an area surrounding that object synchronized with a user generated activation command resulting from user input via the input means, wherein the activated object can be manipulated by user generated commands resulting from user input via the input means. User activation of the object may also be enabled if the user&#39;s gaze point was on or within an area surrounding that object at the predetermined period of time synchronized with a user generated activation command resulting from user input via the input means, wherein the activated object can be manipulated by user generated commands resulting from user input via the input means. 
     According to embodiments of the present invention, when the user touches the touchpad, the location of the initial gaze point is indicated by a visual feedback, such as a crosshairs or similar sign. The user may adjust this initial location by moving the finger on the touchpad. Then, the user may, in a touchscreen like manner, interact with the information presentation area using different gestures. The strength of the visual feedback, e.g. the strength of the light of a crosshairs, may be dependent on where the user&#39;s gaze is located on the information presentation area. For example, if a dragging operation to pan a window is initiated at the gaze point, the visual feedback may initially be discrete. When the dragging operation has been maintained for a period, the visual feedback can be strengthened to indicate for the user where the dragging operation is performed at the moment. 
     In the embodiments including a touchpad, the gestures are finger movements relative the touchpad and each gesture is associated with or corresponds to a particular gesture based control command resulting in a user action. Below, a non-exhaustive number of examples of user actions that can be executed using a combination of gestures and gaze are discussed: 
     By gazing, for example, at an object presented on the information presentation area and by, in connection to this, pressing down and holding a finger on the touchpad during a predetermined period of time, a visual feedback related to that object is presented. For example, by pressing down and holding the finger on the touchpad during a first period of time, the object may be highlighted and, by continue to hold the finger on the touchpad for a second period of time, an information box presenting information regarding the object may be displayed. 
     By gazing, for example, at an object presented on the information presentation area and by in connection to this tapping on the touchpad using a finger, a primary action can be initiated. For example, an application can be opened and started by gazing at an icon representing the application and tapping on the touchpad using a finger. 
     By gazing, for example, at an object presented on the information presentation area and by, in connection to this, lifting a finger (or fingers) that have been in contact with the touchpad, a primary action can be initiated. For example, an application can be opened and started by gazing at an icon representing the application and lifting a finger (or fingers) that have been in contact with the touchpad. 
     The user may slide or drag the view presented by the information presentation area by gazing at the information presentation area and by, in connection to this, sliding his or her finger over the touchpad. The dragging is then initiated at the gaze point of the user. A similar action to slide an object over the information presentation area can be achieved by gazing at the object and by, in connection to this, sliding the finger over the touchpad. Both of these objectives may instead be implemented in a way where two fingers are required to do the swipe, or one finger is used for swiping while another finger holds down a button. 
     The user may select an object for further actions by gazing at the object and by, in connection to this, swiping his or her finger downwards on the touchpad. 
     By gazing at an object or object part presented on the information presentation area and by, in connection to this, pinching with two of his or hers finger, it is possible to zoom that object or object part. The same function can be implemented also on a touchpad only able to sense single touch by having for instance the thumb push a button or keyboard key and the finger moving on the touchpad away from, or towards, the button or keyboard key. 
     By gazing at an object or object part presented on the information presentation area and by, in connection to this, rotating with two of his or hers finger, it is possible to rotate that object or object part. Similarly, when using a touchpad only able to sense single touch the thumb can press a button while a finger moves on the touchpad in a curve at a constant distance from the button to rotate an object. 
     By gazing at an edge of the information presentation area and sliding the finger over the touchpad in the direction that would have been towards the center of the information presentation area if the gesture had been done at the gaze position, a menu or other window hidden during normal use, such as a help menu, can be presented or displayed. That is, a hidden menu or other window can be displayed or presented if the user gazes at, for example, the left edge of the information presentation area and swipes his or her finger over the touchpad in the right direction. 
     By gazing at a slider control, for example a volume control, the finger can be moved up/down (or left/right for a horizontal control) on the touch pad, on a predefined area of a touch screen or above a keyboard to adjust the value of the slider control. 
     By gazing at a checkbox control while doing a “check-gesture” (such as a “V”) on the touchpad, the checkbox can be checked or unchecked. 
     By gazing at a zoomable object or object part presented on the information presentation area and while pressing hard on a pressure sensitive touchpad with one finger (e.g. one of the thumbs), it is possible to zoom in or out on said object using the gaze point as the zoom center point, where each hard press toggles between different zoom levels. 
     By gazing at an object or object part where several options are available, for example “copy” or “rename”, the different options can be displayed on different sides of the object after a preset focusing dwell time has passed or after appropriate user input has been provided. The touchpad or a predefined area of a touch screen is thereafter used to choose action. For example, slide left to copy and slide right to rename. 
     According to another embodiment of the present invention, the gaze tracking module and the user input means are implemented in a touchscreen provided device such as an iPad or similar device. The touchscreen functions both as information presentation area and input device for input of user gestures. A control module is included in the touchscreen provided device and is configured to determine a gaze point area on the information presentation area, i.e. the touchscreen, where the user&#39;s gaze point is located based on the gaze data signals and to execute at least one user action manipulating a view presented on the touchscreen based on the determined gaze point area and at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. The user gestures are inputted via the touchscreen. According to this embodiment, the user gestures, or finger movements on the touchscreen, are relative to the gaze point, which entails a more user friendly and ergonomic use of touchscreen provided devices. For example, the user may hold the device with both hands and interact with graphical user interfaces on the touchscreen using the gaze and movement of the thumbs, where all user actions and activations have the gaze point of the user as starting point. 
     As mentioned, the gesture and gaze initiated actions discussed above are only exemplary and there are a large number of further gestures in combination with gaze point resulting in an action that are conceivable. Below, some further examples are described: 
     Selection of an object or object part can be made by gazing at that object or object part and pressing a finger (e.g. a thumb), fine tuning by moving the finger and releasing the pressure applied by the finger to select that object or object part; 
     Selection of an object or object part can be made by gazing at that object or object part, pressing a finger (e.g. a thumb), fine tuning by moving the finger, using another finger (e.g. the other thumb) to tap for selecting that object or object part. In addition, a double tap may be used for a “double click action” and a quick downward movement may be used for a “right click”. 
     By gazing at a zoomable object or object part presented on the information presentation area while moving a finger (e.g. one of the thumbs) in a circular motion, it is possible to zoom in or out of said object using the gaze point as the zoom center point, where a clockwise motion performs a “zoom in” command and a counterclockwise motion performs a “zoom out” command or vice versa. 
     By gazing at a zoomable object or object part presented on the information presentation area and in connection to this holding one finger (e.g. one of the thumbs) still while moving another finger (e.g. the other thumb) upwards or downwards, it is possible to zoom in or out of said object using the gaze point as the zoom center point, where an upwards motion performs a “zoom in” command and a downwards motion performs a “zoom out” command or vice versa. 
     By gazing at a zoomable object or object part presented on the information presentation area while double-tapping on the touch screen with one finger (e.g. one of the thumbs), it is possible to zoom in or out of said object using the gaze point as the zoom center point, where each double-tap toggles between different zoom levels. 
     By gazing at a zoomable object or object part presented on the information presentation area while sliding two fingers (e.g. the two thumbs) simultaneously in opposite horizontal directions, it is possible to zoom that object or object part. 
     By gazing at a zoomable object and in connection to this holding a finger (e.g. one thumb) still on the touchscreen while moving another finger (e.g. the other thumb) in a circular motion, it is possible to zoom that object or object part. 
     By gazing at an object or object part presented on the information presentation area and in connection to this holding a finger (e.g., one of the thumbs) still on the touchscreen while sliding another finger (e.g. the other thumb), it is possible to slide or drag the view presented by the information presentation area. 
     By gazing at an object or object part presented on the information presentation area and in connection to this holding a finger (e.g., one of the thumbs) still on the touchscreen while sliding another finger (e.g., the other thumb), it is possible to slide or drag the view presented by the information presentation area. 
     By gazing at an object or object part presented on the information presentation area and while tapping or double-tapping with a finger (e.g., one of the thumbs), an automatic panning function can be activated so that the presentation area is continuously slid from one of the edges of the screen towards the center while the gaze point is near the edge of the information presentation area, until a second user input is received. 
     By gazing at an object or object part presented on the information presentation area and while tapping or double-tapping with a finger (e.g., one of the thumbs), the presentation area is instantly slid according to the gaze point (e.g., the gaze point is used to indicate the center of where the information presentation area should be slid). 
     By gazing at a rotatable object or object part presented on the information presentation area while sliding two fingers (e.g., the two thumbs) simultaneously in opposite vertical directions, it is possible to rotate that object or object part. 
     Before the two-finger gesture is performed, one of the fingers can be used to fine-tune the point of action. For example, a user feedback symbol like a “virtual finger” can be shown on the gaze point when the user touches the touchscreen. The first finger can be used to slide around to adjust the point of action relative to the original point. When the user touches the screen with the second finger, the point of action is fixed and the second finger is used for “clicking” on the point of action or for performing two-finger gestures like the rotate, drag and zoom examples above. 
     According to another embodiment of the current invention, the gaze tracking module and the user input means are implemented in a portable device such as an iPad, ultrabook tablet or similar device. However, instead of performing the gestures with the thumbs on the presentation area, one or two separate touchpads are placed on the back side of the device to allow two-finger gestures with other fingers than the thumb. 
     According to another embodiment of the current invention, the gaze tracking module and the user input means are implemented in a vehicle. The information presentation area may be a heads-up display or an infotainment screen. The input means may be one or two separate touch pads on the backside (for use with the index finger/s) or on the front side (for use with the thumb/s) of the steering wheel. 
     According to another embodiment of the current invention, the gaze tracking module and the information presentation area are implemented in a wearable head mounted display that may be designed to look as a pair of glasses (such as the solution described in U.S. Pat. No. 8,235,529). The user input means may include a gyro and be adapted to be worn on a wrist, hand or at least one finger. For example the input means may be a ring with a wireless connection to the glasses (or to a processing unit such as a smart phone that is communicatively connected to the glasses) and a gyro that detects small movements of the finger where the ring is worn. The detected movements representing gesture data may then wirelessly be communicated to the glasses where gaze is detected and gesture based control commands based on the gesture data from the input means is used to identify and execute user action. 
     Normally, in most applications, the touchpad is significantly smaller than the information presentation area, which entails that in certain situations the touchpad may impose limitations on the possible user actions. For example, it may be desired to drag or move an object over the entire information presentation area while the user&#39;s movement of a finger or fingers is limited by the smaller touchpad area. Therefore, in embodiments of the present invention, a touchscreen like session can be maintained despite that the user has removed the finger or fingers from the touchpad if, for example, a specific or dedicated button or keyboard key is held down or pressed. Thereby, it is possible for the user to perform actions requiring multiple touches on the touchpad. For example, an object can be moved or dragged across the entire information presentation area by means of multiple dragging movements on the touchpad. 
     In other embodiments of the present invention, a dragging movement on the information presentation area or other user action is continued after the finger or fingers has reached an edge of the touchpad in the same direction as the initial direction of the finger or fingers. The continued movement or other actions may be continued until an interruption command is delivered, which may be, for example, a pressing down of a keyboard key or button, a tap on the touchpad or when the finger or fingers is removed from the touchpad. 
     In further embodiments of the present invention, the speed of the dragging movement or other action is increased or accelerated when the user&#39;s finger or fingers approaches the edge of the touchpad. The speed may be decreased if the fingers or finger is moved in an opposite direction. 
     In embodiments of the present invention, the action, e.g. a dragging movement of an object, can be accelerated based on gaze position. For example, by gazing at an object, initiating a dragging operation of that object in a desired direction and thereafter gazing at a desired end position for that object, the speed of the object movement will be higher the longer the distance between the initial position of the object and the desired end position is. 
     In other embodiments of the present invention voice commands may be used to choose what action to perform on the object currently being gazed at and then a gesture is required to fulfill the action. For instance a voice command such as the word “move” may allow the user to move the object currently being gazed at by moving a finger over the touchpad or touchscreen. Another action to perform may be to delete an object. In this case the word “delete” may allow deletion of the object currently being gazed at, but additionally a gesture, such as swiping downwards is required to actually delete the object. Thus, the object to act on is chosen by gazing at it, the specific action to perform is chosen by a voice command and the movement to perform or the confirmation is done by a gesture. 
     Another object of the present invention is to provide systems and methods which provide for convenient interaction with a portable device. 
     For the purpose of this invention, any reference to “portable device”, “mobile device” or similar is intended to refer to a computing device that may be carried by a user. This includes, but is not limited to, mobile telephones, tablets, laptops and virtual reality headsets. 
     Although many of the following embodiments refer to gaze or eye tracking, many may also function with a system which determines the position of at least one of a user&#39;s eyes (so-called “eye position”). Further, mere determination of the presence of a user using an image sensor may be sufficient for some embodiments to function correctly. 
     In broad terms, the present invention relates to the following: 
     1. Display information on a portable device. 
     2. Determine the gaze of a user of the portable device, relative to the device. 
     3. Modify information on the portable device based on the gaze of the user. 
     The gaze of a user may be determined using an eye tracking device or components operatively connected with the portable device. For example the components of the eye tracking device may be integrated into the portable device. A typical eye tracking device comprises an image sensor and at least one illuminator, preferably an infrared illuminator, and the image sensor captures an image of at least one eye of the user. Reflections caused by the illuminator or the illuminators may be extracted from the captured image and compared with a feature of the eye in order to determine the user&#39;s gaze direction. Optionally, an illuminator may not be present and merely ambient light used. Any other eye tracking device may also function with the present invention, the concept of eye tracking is not the object of the present invention. 
     For the present invention, any reference to information displayed on a portable device is intended to represent the entire range of information that may be displayed on a display, this includes text, images, video, icons and the like. 
     Further objects and advantages of the present invention will be discussed below by means of exemplifying embodiments. 
     These and other features, aspects and advantages of the invention will be more fully understood when considered with respect to the following detailed description, appended claims and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings are not necessarily drawn to scale and illustrate generally, by way of example, but no way of limitation, various embodiments of the present invention. Thus, exemplifying embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this discussion are not necessarily to the same embodiment, and such references mean at least one. 
         FIG. 1  shows an overview picture of a user controlling a computer apparatus in which the present invention is implemented; 
         FIG. 2  is a block diagram illustrating an embodiment of an arrangement in accordance with the present invention; 
         FIG. 3  is a block diagram illustrating another embodiment of an arrangement in accordance with the present invention; 
         FIG. 4  illustrates an exemplary gesture resulting in a user generated gesture based control command in accordance with the present invention; 
         FIG. 5  illustrates another exemplary gesture resulting in a user generated gesture based control command in accordance with the present invention; 
         FIG. 6  illustrates a further exemplary gesture resulting in a user generated gesture based control command in accordance with the present invention; 
         FIG. 7  illustrates yet another exemplary gesture resulting in a user generated gesture based control command in accordance with the present invention; 
         FIG. 8  illustrates a further exemplary gesture resulting in a user generated gesture based control command in accordance with the present invention; 
         FIG. 9  illustrates another exemplary gesture resulting in a user generated gesture based control command in accordance with the present invention; 
         FIG. 10  illustrates yet another exemplary gesture resulting in a user generated gesture based control command in accordance with the present invention; 
         FIG. 11 a    shows an overview picture of a touchscreen provided device in which a further embodiment of the present invention is implemented; 
         FIG. 11 b    shows an overview picture of a device provided with touchpads on a backside in which a further embodiment of the present invention is implemented; 
         FIG. 12  is a block diagram illustrating the embodiment in accordance with the present invention shown in  FIG. 11   a;    
         FIG. 13 a    is a schematic view of a control module according to an embodiment of the present invention; 
         FIG. 13 b    is a schematic view of a control module according to another embodiment of the present invention; 
         FIG. 13 c    is a schematic view of a control module according to another embodiment of the present invention; 
         FIG. 14  is a schematic view of a wireless transmit/receive unit, WTRU, according to an embodiment of the present invention; 
         FIG. 15 a    is a schematic view of an embodiment of a computer device or handheld device in accordance with an embodiment of the present invention; 
         FIG. 15 b    is a schematic view of another embodiment of a computer device or handheld device in accordance with the present invention; 
         FIG. 16  is a schematic flow chart illustrating steps of an embodiment of a method in accordance with an embodiment of the present invention; 
         FIG. 17  is a schematic flow chart illustrating steps of another embodiment of a method in accordance with the present invention; and 
         FIG. 18  is a schematic flow chart illustrating steps of a further embodiment of a method in accordance with an embodiment of the present invention; 
         FIG. 19  is a schematic flow chart illustrating steps of another embodiment of a method in accordance with an embodiment of the present invention; 
         FIG. 20  is a block diagram illustrating a further embodiment of an arrangement in accordance with the present invention; 
         FIG. 21  is a schematic illustration of yet another implementation of the present invention; 
         FIG. 22  is a schematic illustration of a further implementation of the present invention; and 
         FIG. 23  is a schematic illustration of an implementation of the present invention. 
         FIG. 24  shows a block diagram of one method of the invention for interacting with a portable device. 
         FIG. 25  shows a chart of a method of transitioning between visual indications on a display, when a gaze signal is momentarily lost. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As used herein, the term “module” refers to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software programs, a combinational logic circuit, or other suitable components that provide the described functionality. The term “module” further refers to a specific form of software necessary to practice the methods described herein and particularly the functions described in connection with each specific “module”. It is believed that the particular form of software will be determined primarily by the particular system architecture employed in the system and by the particular methodologies employed by the system according to the present invention. 
     The following is a description of exemplifying embodiments in accordance with the present invention. This description is not to be taken in limiting sense, but is made merely for the purposes of describing the general principles of the invention. It is to be understood that other embodiments may be utilized and structural and logical changes may be made without departing from the scope of the present invention. 
     With reference first to  FIGS. 1, 2, 3 and 20 , embodiments of a computer system according to the present invention will be described.  FIG. 1  shows an embodiment of a computer system with integrated gaze and manual control according to the present invention. The user  110  is able to control the computer system  10  at least partly based on an eye-tracking signal D.sub.EYE, which described the user&#39;s point of regard x, y on an information presentation area or display  20  and based on user generated gestures, i.e. a movement of at least one body part of the user can be detected, generating gesture based control commands via user input means  50  such as a touchpad  51 . 
     In the context of the present invention, as mentioned above, the term “touchpad” (or the term “trackpad”) refers to a pointing device featuring a tactile sensor, a specialized surface that can translate the motion and position of a user&#39;s fingers to a relative position on a screen (information presentation area). Touchpads are a common feature of laptop computers, and are also used as a substitute for a mouse where desk space is scarce. Because they vary in size, they can also be found on personal digital assistants (PDAs) and some portable media players. Wireless touchpads are also available as detached accessories. Touchpads operate in one of several ways, including capacitive sensing and conductance sensing. The most common technology used today entails sensing the capacitive virtual ground effect of a finger, or the capacitance between sensors. While touchpads, like touchscreens, are able to sense absolute position, resolution is limited by their size. For common use as a pointer device, the dragging motion of a finger is translated into a finer, relative motion of the cursor on the screen, analogous to the handling of a mouse that is lifted and put back on a surface. Hardware buttons equivalent to a standard mouse&#39;s left and right buttons are positioned below, above, or beside the touchpad. Netbooks sometimes employ the last as a way to save space. Some touchpads and associated device driver software may interpret tapping the pad as a click, and a tap followed by a continuous pointing motion (a “click-and-a-half”) can indicate dragging. Tactile touchpads allow for clicking and dragging by incorporating button functionality into the surface of the touchpad itself. To select, one presses down on the touchpad instead of a physical button. To drag, instead performing the “click-and-a-half” technique, one presses down while on the object, drags without releasing pressure and lets go when done. Touchpad drivers can also allow the use of multiple fingers to facilitate the other mouse buttons (commonly two-finger tapping for the center button). Some touchpads have “hotspots”, locations on the touchpad used for functionality beyond a mouse. For example, on certain touchpads, moving the finger along an edge of the touch pad will act as a scroll wheel, controlling the scrollbar and scrolling the window that has the focus vertically or horizontally. Apple uses two-finger dragging for scrolling on their trackpads. Also, some touchpad drivers support tap zones, regions where a tap will execute a function, for example, pausing a media player or launching an application. All of these functions are implemented in the touchpad device driver software, and can be disabled. Touchpads are primarily used in self-contained portable laptop computers and do not require a flat surface near the machine. The touchpad is close to the keyboard, and only very short finger movements are required to move the cursor across the display screen; while advantageous, this also makes it possible for a user&#39;s thumb to move the mouse cursor accidentally while typing. Touchpad functionality is available for desktop computers in keyboards with built-in touchpads. 
     Examples of touchpads include one-dimensional touchpads used as the primary control interface for menu navigation on second-generation and later iPod Classic portable music players, where they are referred to as “click wheels”, since they only sense motion along one axis, which is wrapped around like a wheel. In another implementation of touchpads, the second-generation Microsoft Zune product line (the Zune 80/120 and Zune 4/8) uses touch for the Zune Pad. Apple&#39;s PowerBook 500 series was its first laptop to carry such a device, which Apple refers to as a “trackpad”. Apple&#39;s more recent laptops feature trackpads that can sense up to five fingers simultaneously, providing more options for input, such as the ability to bring up the context menu by tapping two fingers. In late 2008 Apple&#39;s revisions of the MacBook and MacBook Pro incorporated a “Tactile Touchpad” design with button functionality incorporated into the tracking surface. 
     The present invention provides a solution enabling a user of a computer system without a traditional touchscreen to interact with graphical user interfaces in a touchscreen like manner using a combination of gaze based input and gesture based user commands. Furthermore, the present invention offers a solution for touchscreen like interaction using gaze input and gesture based input as a complement or an alternative to touchscreen interactions with a computer device having a touchscreen. 
     The display  20  may hence be any type of known computer screen or monitor, as well as combinations of two or more separate displays. For example, the display  20  may constitute a regular computer screen, a stereoscopic screen, a heads-up display (HUD) in a vehicle, or at least one head-mounted display (HMD). 
     The computer  30  may, for example, be any one from the group of a personal computer, computer workstation, mainframe computer, a processor in a vehicle, or a handheld device such as a cell phone, portable music player (such as e.g. an iPod), laptop computers, computer games, electronic books and similar other devices. The present invention may also be implemented in “intelligent environment” where, for example, objects presented on multiple displays can be selected and activated. 
     In order to produce the gaze tracking signal D.sub.EYE, a gaze tracker unit  40  is included in the display  20 , or is associated with the display  20 . A suitable gaze tracker is described in the U.S. Pat. No. 7,572,008, titled “Method and Installation for detecting and following an eye and the gaze direction thereof”, by the same applicant, which hereby is incorporated in its entirety. 
     The software program or software implemented instructions associated with the gaze tracking module  40  may be included within the gaze tracking module  40 . The specific example shown in  FIGS. 2, 3 and 20  illustrates the associated software implemented in a gaze tracking module, which may be included solely in the computer  30 , in the gaze tracking module  40 , or in a combination of the two, depending on the particular application. 
     The computer system  10  comprises a computer device  30 , a gaze tracking module  40 , a display  20 , a control module  36 ,  36 ′ and user input means  50 ,  50 ′ as shown in  FIGS. 2, 3 and 20 . The computer device  30  comprises several other components in addition to those illustrated in  FIGS. 2 and 20  but these components are omitted from  FIGS. 2, 3 and 20  in illustrative purposes. 
     The user input means  50 ,  50 ′ comprises elements that are sensitive to pressure, physical contact, gestures, or other manual control by the user, for example, a touchpad  51 . Further, the input device means  50 ,  50 ′ may also include a computer keyboard, a mouse, a “track ball”, or any other device, for example, an IR-sensor, voice activated input means, or a detection device of body gestures or proximity based input can be used. However, in the specific embodiments shown in  FIGS. 2, 3 and 20 , a touchpad  51  is included in the user input device  50 ,  50 ′. 
     An input module  32 , which may be a software module included solely in a control module  36 ′ or in the user input means  50  or as a module separate from the control module and the input means  50 ′, is configured to receive signals from the touchpad  51  reflecting a user&#39;s gestures. Further, the input module  32  is also adapted to interpret the received signals and provide, based on the interpreted signals, gesture based control commands, for example, a tap command to activate an object, a swipe command or a slide command. 
     If the input module  32  is included in the input means  50 , gesture based control commands are provided to the control module  36 , see  FIG. 2 . In embodiments of the present invention, the control module  36 ′ includes the input module  32  based on gesture data from the user input means  50 ′, see  FIG. 3 . 
     The control module  36 ,  36 ′ is further configured to acquire gaze data signals from the gaze tracking module  40 . Further, the control module  36 ,  36 ′ is configured to determine a gaze point area  120  on the information presentation area  20  where the user&#39;s gaze point is located based on the gaze data signals. The gaze point area  120  is preferably, as illustrated in  FIG. 1 , a local area around a gaze point of the user. 
     Moreover, the control module  36 ,  36 ′ is configured to execute at least one user action manipulating a view presented on the graphical information presentation area  20  based on the determined gaze point area and the at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. The control module  36 ,  36 ′ may be integrated in the computer device  30  or may be associated or coupled to the computer device  30 . 
     Hence, the present invention allows a user to interact with a computer device  30  in touchscreen like manner, e.g. manipulate objects presented on the information presentation area  20 , using gaze and gestures, e.g. by moving at least one finger on a touchpad  51 . 
     Preferably, when the user touches the touchpad  51 , the location of the initial gaze point is indicated by a visual feedback, such as a crosshairs or similar sign. This initial location can be adjusted by moving the finger on the touchpad  51 . Thereafter, the user can, in a touchscreen like manner, interact with the information presentation area  20  using different gestures and the gaze. In the embodiment including a touchpad, the gestures are finger movements relative the touchpad  51  and each gesture is associated with or corresponds to particular gesture based user command resulting in a user action. 
     Below, a non-exhaustive number of examples of user actions that can be executed using a combination of gestures and gaze will be discussed with regard to  FIG. 4-10 : 
     By gazing, for example, at an object presented on the information presentation area  20  and by in connection to this, touching the touchpad or pressing down and holding a finger  60  (see  FIG. 4 ) on the touchpad  51  during a period of y ms, that object is highlighted. If the finger  60  is held down during a second period of z ms, an information box may be displayed presenting information regarding that object. In  FIG. 4 , this gesture is illustrated in relation to a touchpad  51 . 
     By gazing, for example, at an object presented on the information presentation area  20  and by in connection to this tapping on the touchpad  51  using a finger  71 , a primary action can be initiated. For example, an application can be opened and started by gazing at an icon representing the application and tapping on the touchpad  51  using a finger. In  FIG. 5 , this gesture is illustrated in relation to a touchpad  51 . 
     The user may slide or drag the view presented by the information presentation area  20  by gazing somewhere on the information presentation area  20  and by, in connection to this, sliding his or her finger  81  over the touchpad  51 . A similar action to slide an object over the information presentation area  20  can be achieved by gazing at the object and by, in connection to this, sliding the finger  81  over the touchpad  51 . This gesture is illustrated in  FIG. 6  in relation to the touchpad  51 . Of course, this gesture can be executed by means of more than one finger, for example, by using two fingers. 
     The user may select an object for further actions by gazing at the object and by, in connection to this, swiping his or her finger  91  on the touchpad  51  in a specific direction. This gesture is illustrated in  FIG. 7  in relation to the touchpad  51 . Of course, this gesture can be executed by means of more than one finger, for example, by using two fingers. 
     By gazing at an object or object part presented on the information presentation area  20  and by, in connection to this, pinching with two of his or hers finger  101  and  102 , it is possible to zoom out that object or object part. This gesture is illustrated in  FIG. 8  in relation to the touchpad  51 . Similarly, by gazing at an object or object part presented on the information presentation area  20  and by, in connection to this, moving the fingers  101  and  102  apart, it is possible to expand or zoom in that object or object part. 
     By gazing at an object or object part presented on the information presentation area  20  and by, in connection to this, rotating with two of his or hers finger  111  and  112 , it is possible to rotate that object or object part. This gesture is illustrated in  FIG. 9  in relation to the touchpad  51 . 
     By gazing at an edge or frame part of the information presentation area  20  or at an area in proximity to the edge or frame and, in connection to this, sliding his or her finger or fingers  124  on the touchpad  51  in a direction which if performed at the point of gaze would have been from the edge towards a center of the information presentation area a menu may come in from the edge. 
     By gazing at a slider control, for example a volume control, the finger can be moved up/down (or left/right for a horizontal control) to adjust the value of the slider control. With appropriate input means this gesture can be detected on a touchpad, on a touch screen or in air without physically touching the input means. 
     By gazing at a checkbox control while doing a “check-gesture” (such as a “V”) on the touchpad, the checkbox can be checked or unchecked. With appropriate input means this gesture can be detected on a touchpad, on a touch screen or in air without physically touching the input means. 
     By gazing at an object or object part where several options are available, for example “copy” or “rename”, the different options can be displayed on different sides of the object after a preset focusing dwell time has passed or after appropriate user input has been provided. Thereafter a gesture is done to choose action. For example, swipe left to copy and swipe right to rename. With appropriate input means this gesture can be detected on a touchpad, on a touch screen or in air without physically touching the input means. By pressing the finger harder on the touchpad, i.e. increasing the pressure of a finger touching the touchpad, a sliding mode can be initiated. For example, by gazing at an object, touching the touchpad, increasing the pressure on the touchpad and moving the finger or finger over the touchscreen, the object can be moved or dragged over the information presentation area. When the user removes the finger from the touchpad  51 , the touchscreen like session is finished. The user may thereafter start a new touchscreen like session by gazing at the information presentation area  20  and placing the finger on the touchpad  51 . 
     As mentioned, the gesture and gaze initiated actions discussed above are only exemplary and there are a large number of further gestures in combination with gaze point resulting in an action that are conceivable. With appropriate input means many of these gestures can be detected on a touchpad, on a predefined area of a touch screen, in air without physically touching the input means, or by an input means worn on a finger or a hand of the user. Below, some further examples are described: 
     Selection of an object or object part can be made by gazing at that object or object part and pressing a finger (e.g. a thumb), fine tuning by moving the finger and releasing the pressure applied by the finger to select that object or object part; 
     Selection of an object or object part can be made by gazing at that object or object part, pressing a finger (e.g. a thumb), fine tuning by moving the finger, using another finger (e.g. the other thumb) to tap for selecting that object or object part. In addition, a double tap may be used for a “double click action” and a quick downward movement may be used for a “right click”. 
     By gazing at a zoomable object or object part presented on the information presentation area while moving a finger (e.g. one of the thumbs) in a circular motion, it is possible to zoom in or out of the said object using the gaze point as the zoom center point, where a clockwise motion performs a “zoom in” command and a counterclockwise motion performs a “zoom out” command or vice versa. 
     By gazing at a zoomable object or object part presented on the information presentation area and in connection to this holding one finger (e.g. one of the thumbs) still while moving another finger (e.g. the other thumb) upwards and downwards, it is possible to zoom in or out of the said object using the gaze point as the zoom center point, where an upwards motion performs a “zoom in” command and a downwards motion performs a “zoom out” command or vice versa. 
     By gazing at a zoomable object or object part presented on the information presentation area and while pressing hard on a pressure-sensitive touchpad with one finger (e.g. one of the thumbs), it is possible to zoom in or out on the said object using the gaze point as the zoom center point, where each hard press toggles between different zoom levels. 
     By gazing at a zoomable object or object part presented on the information presentation area while double-tapping on a touchpad with one finger (e.g. one of the thumbs), it is possible to zoom in or out of the said object using the gaze point as the zoom center point, where each double-tap toggles between different zoom levels. 
     By gazing at a zoomable object or object part presented on the information presentation area while sliding two fingers (e.g. the two thumbs) simultaneously in opposite horizontal directions, it is possible to zoom that object or object part. 
     By gazing at a zoomable object and in connection to this holding finger (e.g. one thumb) still on the touchscreen while moving another finger (e.g. the other thumb) in a circular motion, it is possible to zoom that object or object part. 
     By gazing at an object or object part presented on the information presentation area and in connection to this holding a finger (e.g., one of the thumbs) still on the touchscreen while sliding another finger (e.g., the other thumb), it is possible to slide or drag the view presented by the information presentation area. 
     By gazing at an object or object part presented on the information presentation area and in connection to this holding a finger (e.g., one of the thumbs) still on the touchscreen while sliding another finger (e.g., the other thumb), it is possible to slide or drag the view presented by the information presentation area. 
     By gazing at an object or object part presented on the information presentation area and while tapping or double-tapping with a finger (e.g., one of the thumbs), an automatic panning function can be activated so that the presentation area is continuously slided from one of the edges of the screen towards the center while the gaze point is near the edge of the information presentation area, until a second user input is received. 
     By gazing at an object or object part presented on the information presentation area and while tapping or double-tapping with a finger (e.g., one of the thumbs), the presentation area is instantly slid according to the gaze point (e.g., the gaze point is used to indicate the center of where the information presentation area should be slid). 
     By gazing at a rotatable object or object part presented on the information presentation area while sliding two fingers (e.g. the two thumbs) simultaneously in opposite vertical directions, it is possible to rotate that object or object part. 
     Before the two-finger gesture is performed, one of the fingers can be used to fine-tune the point of action. For example, a user feedback symbol like a “virtual finger” can be shown on the gaze point when the user touches the touchscreen. The first finger can be used to slide around to adjust the point of action relative to the original point. When user touches the screen with the second finger, the point of action is fixed and the second finger is used for “clicking” on the point of action or for performing two-finger gestures like the rotate, drag and zoom examples above. 
     In embodiments of the present invention, the touchscreen like session can be maintained despite that the user has removed the finger or fingers from the touchpad if, for example, a specific or dedicated button or keyboard key is held down or pressed. Thereby, it is possible for the user to perform actions requiring multiple touches on the touchpad. For example, an object can be moved or dragged across the entire information presentation area by means of multiple dragging movements on the touchpad. 
     With reference now to  FIGS. 11 a , 11 b    and  12 , further embodiments of the present invention will be discussed.  FIG. 11 a    shows a further embodiment of a system with integrated gaze and manual control according to the present invention. This embodiment of the system is implemented in a device  100  with a touchscreen  151  such as an iPad or similar device. The user is able to control the device  100  at least partly based on gaze tracking signals which describes the user&#39;s point of regard x, y on the touchscreen  151  and based on user generated gestures, i.e. a movement of at least one body part of the user can be detected, generating gesture based control commands via user input means  150  including the touchscreen  151 . 
     The present invention provides a solution enabling a user of a device  100  with a touchscreen  151  to interact with a graphical user interfaces using gaze as direct input and gesture based user commands as relative input. Thereby, it is possible, for example, to hold the device  100  with both hands and interact with a graphical user interface  180  presented on the touchscreen with gaze and the thumbs  161  and  162  as shown in  FIG. 11   a.    
     In an alternative embodiment, one or more touchpads  168  can be arranged on the backside of the device  100 ′, i.e. on the side of the device on which the user normally do not look at during use. This embodiment is illustrated in  FIG. 11 b   . Thereby, a user is allowed to control the device at least partly based on gaze tracking signals which describes the user&#39;s point of regard x, y on the information presentation area and based on user generated gestures, i.e. a movement of at least one finger on the one or more touchpads  168  on the backside of the device  100 ′, generating gesture based control commands interpreted by the control module. In order to produce the gaze tracking signal, a gaze tracking module  140  is included in the device  100 ,  100 ′. A suitable gaze tracker is described in the U.S. Pat. No. 7,572,008, titled “Method and Installation for detecting and following an eye and the gaze direction thereof”, by the same applicant, which hereby is incorporated in its entirety. 
     The software program or software implemented instructions associated with the gaze tracking module  140  may be included within the gaze tracking module  140 . 
     The device  100  comprises a gaze tracking module  140 , user input means  150  including the touchscreen  151  and an input module  132 , and a control module  136  as shown in  FIG. 12 . The device  100  comprises several other components in addition to those illustrated in  FIG. 12  but these components are omitted from  FIG. 12  in illustrative purposes. 
     The input module  132 , which may be a software module included solely in a control module or in the user input means  150 , is configured to receive signals from the touchscreen  151  reflecting a user&#39;s gestures. Further, the input module  132  is also adapted to interpret the received signals and provide, based on the interpreted signals, gesture based control commands, for example, a tap command to activate an object, a swipe command or a slide command. 
     The control module  136  is configured to acquire gaze data signals from the gaze tracking module  140  and gesture based control commands from the input module  132 . Further, the control module  136  is configured to determine a gaze point area  180  on the information presentation area, i.e. the touchscreen  151 , where the user&#39;s gaze point is located based on the gaze data signals. The gaze point area  180  is preferably, as illustrated in  FIG. 1 , a local area around a gaze point of the user. 
     Moreover, the control module  136  is configured to execute at least one user action manipulating a view presented on the touchscreen  151  based on the determined gaze point area and the at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. All user actions described in the context of this application may also be executed with this embodiment of the present invention. 
     In a possible further embodiment, when the user touches the touchscreen  151 , the location of the initial gaze point is indicated by a visual feedback, such as a crosshairs or similar sign. This initial location can be adjusted by moving the finger on the touchscreen  151 , for example, using a thumb  161  or  162 . Thereafter, the user can interact with the touchscreen  151  using different gestures and the gaze, where the gaze is the direct indicator of the user&#39;s interest and the gestures are relative to the touchscreen  151 . In the embodiment including a touchscreen, the gestures are finger movements relative the touchscreen  151  and each gesture is associated with or corresponds to particular gesture based user command resulting in a user action. 
     With reference now to  FIGS. 13 a , 13 b  and 13 c   , control modules for generating gesture based commands during user interaction with an information presentation area  201 , for example, associated with a WTRU (described below with reference to  FIG. 14 ), or a computer device or handheld portable device (described below with reference to  FIG. 15 a    or  15   b ), or in a vehicle (described below with reference to  FIG. 21 ), or in a wearable head mounted display (described below with reference to  FIG. 22 ) will be described. Parts or modules described above will not be described in detail again in connection to this embodiment. 
     According to an embodiment of the present invention shown in  FIG. 13 a   , the control module  200  is configured to acquire user input from input means  205 , for example, included in a device in which the control module may be arranged in, adapted to detect user generated gestures. For this purpose, the control module  200  may include an input module  232  comprising a data acquisition module  210  configured to translate the gesture data from the input means  205  into an input signal. The input means  205  may include elements that are sensitive to pressure, physical contact, gestures, or other manual control by the user, for example, a touchpad. Further, the input means  205  may also include a computer keyboard, a mouse, a “track ball”, or any other device, for example, an IR-sensor, voice activated input means, or a detection device of body gestures or proximity based input can be used. 
     Further, the input module  232  is configured to determine at least one user generated gesture based control command based on the input signal. For this purpose, the input module  232  further comprises a gesture determining module  220  communicating with the data acquisition module  210 . The gesture determining module  220  may also communicate with the gaze data analyzing module  240 . The gesture determining module  220  may be configured to check whether the input signal corresponds to a predefined or predetermined relative gesture and optionally use gaze input signals to interpret the input signal. For example, the control module  200  may comprise a gesture storage unit (not shown) storing a library or list of predefined gestures, each predefined gesture corresponding to a specific input signal. Thus, the gesture determining module  220  is adapted to interpret the received signals and provide, based on the interpreted signals, gesture based control commands, for example, a tap command to activate an object, a swipe command or a slide command. 
     A gaze data analyzing module  240  is configured to determine a gaze point area on the information presentation area  201  including the user&#39;s gaze point based on at least the gaze data signals from the gaze tracking module  235 . The information presentation area  201  may be a display of any type of known computer screen or monitor, as well as combinations of two or more separate displays, which will depend on the specific device or system in which the control module is implemented in. For example, the display  201  may constitute a regular computer screen, a stereoscopic screen, a heads-up display (HUD) in a vehicle, or at least one head-mounted display (HMD). Then, a processing module  250  may be configured to execute at least one user action manipulating a view presented on the information presentation area  201  based on the determined gaze point area and at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. Hence, the user is able to control a device or system at least partly based on an eye-tracking signal which described the user&#39;s point of regard x, y on the information presentation area or display  201  and based on user generated gestures, i.e. a movement of at least one body part of the user can be detected, generating gesture based control commands via user input means  205  such as a touchpad. 
     According to another embodiment a control module according to the present invention shown in  FIG. 13 b   , the control module  260  is configured to acquire gesture based control commands from an input module  232 ′. The input module  232 ′ may comprise a gesture determining module and a data acquisition module as described above with reference to  FIG. 13 a   . A gaze data analyzing module  240  is configured to determine a gaze point area on the information presentation area  201  including the user&#39;s gaze point based on at least the gaze data signals received from the gaze tracking module  235 . The information presentation area  201  may be a display of any type of known computer screen or monitor, as well as combinations of two or more separate displays, which will depend on the specific device or system in which the control module is implemented in. For example, the display  201  may constitute a regular computer screen, a stereoscopic screen, a heads-up display (HUD) in a vehicle, or at least one head-mounted display (HMD). A processing module  250  may be configured to execute at least one user action manipulating a view presented on the information presentation area  201  based on the determined gaze point area and at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. Hence, the user is able to control a device or system at least partly based on an eye-tracking signal which described the user&#39;s point of regard x, y on the information presentation area or display  201  and based on user generated gestures, i.e. a movement of at least one body part of the user can be detected, generating gesture based control commands via user input means  205  such as a touchpad. 
     With reference to  FIG. 13 c   , a further embodiment of a control module according to the present invention will be discussed. The input module  232 ″ is distributed such that the data acquisition module  210  is provided outside the control module  280  and the gesture determining module  220  is provided in the control module  280 . A gaze data analyzing module  240  is configured to determine a gaze point area on the information presentation area  201  including the user&#39;s gaze point based on at least the gaze data signals received from the gaze tracking module  235 . The information presentation area  201  may be a display of any type of known computer screen or monitor, as well as combinations of two or more separate displays, which will depend on the specific device or system in which the control module is implemented in. For example, the display  201  may constitute a regular computer screen, a stereoscopic screen, a heads-up display (HUD) in a vehicle, or at least one head-mounted display (HMD). A processing module  250  may be configured to execute at least one user action manipulating a view presented on the information presentation area  201  based on the determined gaze point area and at least one user generated gesture based control command, wherein the user action is executed with the determined gaze point area as a starting point. Hence, the user is able to control a device or system at least partly based on an eye-tracking signal which described the user&#39;s point of regard x, y on the information presentation area or display  201  and based on user generated gestures, i.e. a movement of at least one body part of the user can be detected, generating gesture based control commands via user input means  205  such as a touchpad. 
     With reference to  FIG. 14 , a wireless transmit/receive unit (WTRU) such as a cellular telephone or a smartphone, in accordance with the present invention will be described. Parts or modules described above will not be described in detail again. Further, only parts or modules related to the present invention will be described below. Accordingly, the WTRU includes a large number of additional parts, units and modules that are not described herein such as antennas and transmit/receive units. The wireless transmit/receive unit (WTRU)  300  is associated with an information presentation area  301  and further comprises input means  305 , including e.g. an input module as has been described above, adapted to detect user generated gestures and a gaze tracking module  325  adapted to detect gaze data of a viewer of the information presentation area  301 . The WTRU further comprises a control module  200 ,  260  or  280  as described above with reference to  FIGS. 13 a , 13 b  and 13 c   . The user is able to control the WTRU at least partly based on an eye-tracking signal which describes the user&#39;s point of regard x, y on the information presentation area or display  301  and based on user generated gestures, i.e. a movement of at least one body part of the user can be detected, generating gesture based control commands via user input means  305  such as a touchpad. All user actions described in the context of this application may also be executed with this embodiment of the present invention. 
     With reference to  FIGS. 15 a  and 15 b   , a computer device or handheld portable device in accordance with the present invention will be described. Parts or modules described above will not be described in detail again. Further, only parts or modules related to the present invention will be described below. Accordingly, the device includes a large number of additional parts, units and modules that are not described herein such as memory units (e.g. RAM/ROM), or processing units. The computer device or handheld portable device  400  may, for example, be any one from the group of a personal computer, computer workstation, mainframe computer, a processor or device in a vehicle, or a handheld device such as a cell phone, smartphone or similar device, portable music player (such as e.g. an iPod), laptop computers, computer games, electronic books, an iPAD or similar device, a Tablet, a Phoblet/Phablet. 
     The computer device or handheld device  400   a  is connectable to an information presentation area  401   a  (e.g. an external display or a heads-up display (HUD), or at least one head-mounted display (HMD)), as shown in  FIG. 15 a   , or the computer device or handheld device  400   b  includes an information presentation area  401   b , as shown in  FIG. 15 b   , such as a regular computer screen, a stereoscopic screen, a heads-up display (HUD), or at least one head-mounted display (HMD). Furthermore, the computer device or handheld device  400   a ,  400   b  comprises input means  405  adapted to detect user generated gestures and a gaze tracking module  435  adapted to detect gaze data of a viewer of the information presentation area  401 . Moreover, the computer device or handheld device  400   a ,  400   b  comprises a control module  200 ,  260 , or  280  as described above with reference to  FIG. 13 a , 13 b    or  13   c . The user is able to control the computer device or handheld device  400   a ,  400   b  at least partly based on an eye-tracking signal which described the user&#39;s point of regard x, y on the information presentation area or display  401  and based on user generated gestures, i.e. a movement of at least one body part of the user can be detected, generating gesture based control commands via user input means  405  such as a touchpad. All user actions described in the context of this application may also be executed with this embodiment of the present invention. 
     With reference now to  FIG. 16-19 , example embodiments of methods according to the present invention will be described. The method embodiments described in connection with  FIGS. 16-19  are implemented in an environment where certain steps are performed in a device, e.g. a WTRU described above with reference to  FIG. 14 , or a computer device or handheld device described above with reference to  FIG. 15 a    or  15   b  and certain steps are performed in a control module, e.g. a control module as described above with reference to  FIGS. 13 a , 13 b  and 13 c   . As the skilled person realizes, the methods described herein can also be implemented in other environments, as, for example, in a system as described above with reference to  FIGS. 2, 3 and 20  or in implementations illustrated in  FIGS. 21-23 . Similar or like steps performed in the different embodiments will be denoted with the same reference numeral hereinafter. 
     With reference first to  FIG. 16 , the device is waiting for user input in step S 500 . In step S 510 , the user touches a touch sensitive area on the device (e.g. input means as described above) with one or more fingers of each hand. This step is not a part of the method according to embodiments of the invention. There are a large number of conceivable gestures that the user can use to control actions of the device, and a non-exhaustive number of such gestures have been described above. At step S 520 , the gesture data, i.e. the user input, is translated into an input signal. At step S 530 , it is checked whether the input signal corresponds to a predefined or predetermined relative gesture. If not, the procedure returns back to step S 500 . On the other hand, if yes (i.e. the input signal corresponds to a predefined gesture), a gesture based control command is generated at step S 570 . At step S 540 , the user looks at a screen or an information presentation area and at step S 550  the user&#39;s gaze is detected at the information presentation area. The step S 540  is not a part of the method according to embodiments of the present invention. In step S 560 , a gaze point area including a user&#39;s point of gaze on the screen or information presentation area. At step S 580 , an action corresponding to the relative gesture at the user&#39;s point of gaze is performed based on the gesture based control command and the determined gaze point at the information presentation area. 
     With reference to  FIG. 17 , the device is waiting for user input in step S 500 . In step S 590 , the user makes a gesture with one or more fingers and/or at least one hand in front of the information presentation area (which gesture is interpreted by input means as described above). The step S 590  is not a part of the method according to embodiments of the present invention. There are a large number of conceivable gestures that the user can use to control actions of the device, and a non-exhaustive number of such gestures have been described above. At step S 520 , the gesture data, i.e. the user input, is translated into an input signal. At step S 530 , it is checked whether the input signal corresponds to a predefined or predetermined relative gesture. If not, the procedure returns back to step S 500 . On the other hand, if yes (i.e. the input signal corresponds to a predefined gesture), a gesture based control command is generated at step S 570 . At step S 540 , the user looks at a screen or an information presentation area and at step S 550  the user&#39;s gaze is detected at the information presentation area. As mentioned above, the step S 540  is not a part of the method according to embodiments of the present invention. In step S 560 , a gaze point area including a user&#39;s point of gaze on the screen or information presentation area. At step S 580 , an action corresponding to the relative gesture at the user&#39;s point of gaze is performed based on the gesture based control command and the determined gaze point at the information presentation area. 
     With reference to  FIG. 18 , the device is waiting for user input in step S 500 . In step S 592 , the user generates input by touching touchpad or predefined area of touch-screen. The step S 592  is not a part of the method according to embodiments of the present invention. There are a large number of conceivable gestures that the user can use to control actions of the device, and a non-exhaustive number of such gestures have been described above. At step S 520 , the gesture data, i.e. the user input, is translated into an input signal. At step S 530 , it is checked whether the input signal corresponds to a predefined or predetermined relative gesture. If not, the procedure returns back to step S 500 . On the other hand, if yes (i.e. the input signal corresponds to a predefined gesture), a gesture based control command is generated at step S 570 . At step S 540 , the user looks at a screen or an information presentation area and at step S 550  the user&#39;s gaze is detected at the information presentation area. The step S 540  is not a part of the method according to embodiments of the present invention. In step S 560 , a gaze point area including a user&#39;s point of gaze on the screen or information presentation area is determined. At step S 580 , an action corresponding to the relative gesture at the user&#39;s point of gaze is performed based on the gesture based control command and the determined gaze point at the information presentation area. 
     With reference to  FIG. 19 , the device is waiting for user input in step S 500 . In step S 594 , the user generates input by making a gesture with one or more of his or hers fingers and/or at least one hand. The step S 594  is not a part of the method according to embodiments of the present invention. There are a large number of conceivable gestures that the user can use to control actions of the device, and a non-exhaustive number of such gestures have been described above. At step S 520 , the gesture data, i.e. the user input, is translated into an input signal. At step S 530 , it is checked whether the input signal corresponds to a predefined or predetermined relative gesture. If not, the procedure returns back to step S 500 . On the other hand, if yes (i.e. the input signal corresponds to a predefined gesture), a gesture based control command is generated at step S 570 . At step S 540 , the user looks at a screen or an information presentation area and at step S 550  the user&#39;s gaze is detected at the information presentation area. The step S 540  is not a part of the method according to embodiments of the present invention. In step S 560 , a gaze point area including a user&#39;s point of gaze on the screen or information presentation area is determined. At step S 580 , an action corresponding to the relative gesture at the user&#39;s point of gaze is performed based on the gesture based control command and the determined gaze point at the information presentation area. 
     With reference to  FIG. 21 , a further implementation of the present invention will be discussed. A gaze tracking module (not shown) and a user input means  900  are implemented in a vehicle (not shown). The information presentation area (not shown) may be a heads-up display or an infotainment screen. The input means  900  may be one or two separate touch pads on the backside (for use with the index finger/s) or on the front side (for use with the thumb/s) of the steering wheel  910  of the vehicle. A control module  950  is arranged in a processing unit configured to be inserted into a vehicle or a central processing unit of the vehicle. Preferably, the control module is a control module as described with reference to  FIGS. 13 a   - 13   c.    
     With reference to  FIG. 22 , another implementation of the present invention will be discussed. A gaze tracking module (not shown) and an information presentation area (not shown) are implemented in a wearable head mounted display  1000  that may be designed to look as a pair of glasses. One such solution is described in U.S. Pat. No. 8,235,529. The user input means  1010  may include a gyro and be adapted to be worn by the user  1020  on a wrist, hand or at least one finger. For example, the input means  1010  may be a ring with a wireless connection to the glasses and a gyro that detects small movements of the finger where the ring is worn. The detected movements representing gesture data may then wirelessly be communicated to the glasses where gaze is detected and gesture based control commands based on the gesture data from the input means is used to identify and execute user action. Preferably, a control module as described with reference to  FIG. 13 a -13 c    is used with this implementation. 
     With reference to  FIG. 23 , an implementation of the present invention will be discussed. In this implementation, the user  1120  is able to control a computer device  1100  at least partly based on an eye-tracking signal which describes the user&#39;s point of regard x, y on an information presentation area  1140  and based on user generated gestures, i.e. a movement of at least one body part of the user can be detected, generating gesture based control commands via user input means  1150 . In this embodiment, the user  1120  can generate the gesture based control commands by performing gestures above or relative the keyboard of the computer device  1100 . The input means  1140  detects the gestures, for example, using an optical measurement technique or capacitive measurement technique. Preferably, a control module as described with reference to  FIG. 13 a -13 c    is used with this implementation and may be arranged in the computer device  1100 . The computer device  1100  may, for example, be any one from the group of a personal computer, computer workstation, mainframe computer, or a handheld device such as a cell phone, portable music player (such as e.g. an iPod), laptop computers, computer games, electronic books and similar other devices. The present invention may also be implemented in an “intelligent environment” where, for example, objects presented on multiple displays can be selected and activated. In order to produce the gaze tracking signals, a gaze tracker unit (not shown) is included in the computer device  1100 , or is associated with the information presentation area  1140 . A suitable gaze tracker is described in the U.S. Pat. No. 7,572,008, titled “Method and Installation for detecting and following an eye and the gaze direction thereof”, by the same applicant, which hereby is incorporated in its entirety. While this specification contains a number of specific embodiments, these should not be construed as limitation to the scope of the present invention or of what may be claimed, but rather as descriptions of features specific to exemplary implementations of the present invention. Certain features that are described in this specification in the context of separate implementations can also be implemented in combinations in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable sub-combination. Moreover, although feature may be described above as acting in certain combinations or even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination. 
     Embodiments Involving User Recognition 
     According to a further embodiment of the present invention, there is provided a system and method for adapting the interface of a portable device based on information derived from a user&#39;s gaze. The system comprises a portable device containing, or operatively linked to, an eye tracking device, where the eye tracking device is adapted to determine a user&#39;s gaze relative to the portable device. Preferably the portable device contains a display, and a module for displaying information on that display. This module is typically part of an operating system. Popular operating systems include the Google Android™ and Apple iOS™ operating systems. A module in the portable device operatively connected with the eye tracking device compares a user&#39;s gaze information with information displayed on the portable device display at the time of the user&#39;s gaze. The user&#39;s gaze or eye information may be used to identify or otherwise log the user in to a portable device. For example, a gaze pattern may be used to identify a user, iris identification may be used, or facial identification using facial features may be used, as would be readily understood by a person of skill in the art. 
     Further, a user may be identified through non-gaze means, such as traditional pattern or password based login procedures. 
     Once the operating system, or other application executed on the portable device, is able to determine the identity of the user, information displayed may be modified based on that identity. This modified information may be combined with gaze information of the user, to provide for an improved user experience. For example, if a user is recognized by the device, when the device is in a limited mode such as a locked mode, more information is displayed than if a user is not recognized by the device. 
     By way of example, a user may be identified and the history of that user&#39;s usage of the portable device logged. This identification can be used in many contexts. For example, the identity of the user may be provided to applications running on the protable device, the applications may then modify their behavior or store the usage information for the particular user. As a further example, when the user gazes at a contact in a phone application, that is either linked to the user&#39;s profile or frequently contacted, the phone application may instantly place a video or audio call and display the call on the display. 
     User identification may be utilized to identify a user in the context of a website or other application. For example a shopping application or website may determine a user is the registered owner of an account based on the user&#39;s eyes (for example iris identification) or gaze pattern. The application or website may also sign a user out, once the portable device determines the user is no longer gazing at the application or website within a predefined period of time, or that the original user to open the application or website is no longer present in front of the device. 
     Embodiments Involving Adaption of a User Interface 
     According to a further embodiment of the present invention, there is provided a system and method for adapting the interface of a portable device based on information derived from a user&#39;s gaze. The system comprises a portable device containing, or operatively linked to, an eye tracking device, where the eye tracking device is adapted to determine a user&#39;s gaze relative to the portable device. Preferably the portable device contains a display, and a module for displaying information on that display. This module is typically part of an operating system. Popular operating systems include the Google Android™ and Apple iOS™ operating systems. A module in the portable device operatively connected with the eye tracking device compares a user&#39;s gaze information with information displayed on the portable device display at the time of the user&#39;s gaze. This data is collected over time and may be analyzed by the portable device according to the present invention, in order to alter further information shown on the display. 
     In this way, the portable device, or software executed on the portable device, may define that certain information has been “seen”. Information that has been seen has not necessarily been read or understood by a user, but has merely been noticed by the user. Any seen information could be removed, or altered in how it is displayed until a user determines to read the information in more detail. 
     By way of example, the portable device may determine that the user is gazing at an email application and thus may show unread emails. By way of a further example, the portable device may determine that a user typically gazes at unread emails before gazing at unread messages, and thus may make unread emails appear before unread messages. 
     As a further example, an application running on the portable device may display information about the weather. When a user gazes at an item in the application, such as an icon, the item animates. For example, if the weather is warm a picture of a sun may move. 
     As a further example, an application running on the portable device may display an avatar (an image of a person). When a user gazes at the avatar, it may instead display a view from an image sensor on the portable device (for example, an image of the user of the portable device). Alternatively, the avatar may animate so as to react differently to the location of the user&#39;s gaze on the avatar. 
     As a further example, an application running on the portable device may display images, or reduced resolution versions of images. These images may have been captured by an image sensor incorporated in the portable device, or collected by the device in other ways, such as downloaded from the internet. The application may sort display of these images according to the amount of times they have been viewed, the duration they have been viewed for, or any other metric definable by a user&#39;s gaze. 
     As a further example, a user may use an application containing summaries of further information, for example an application showing thumbnails (reduced resolution versions) of images, upon gazing at a thumbnail the full resolution image of that thumbnail, or related images, may be displayed. 
     As a further example, the portable device may have an image displayed, such as a background image. As a user gazes at the image, the image may dynamically modify in line with the user&#39;s gaze. For example, consider an image of a night sky containing a plurality of stars. As the user gazes across the image, the starts located at the user&#39;s gaze may highlight by changing size, shape, color etc. 
     As a further example, information may be maintained on a display for as long as a users&#39; gaze remains fixated on or near the information. 
     As a further example, information may be relayed to a remote person or location regarding the user&#39;s gaze information. For example, an application allowing text communication between two or more parties, such as an SMS application, may display on a remote device that a message is being read or otherwise gazed at by a user of a local device. 
     Embodiments Involving the Use of Gaze to Determine Intention 
     According to a further embodiment of the present invention there is provided a system and method for adapting the interface of a portable device based on information derived from a user&#39;s gaze. The system comprises a portable device containing, or operatively linked to, an eye tracking device, where the eye tracking device is adapted to determine a user&#39;s gaze relative to the portable device. Preferably the portable device contains a display, and a module for displaying information on that display. This module is typically part of an operating system. Popular operating systems include the Google Android™ and Apple iOS™ operating systems. A module in the portable device operatively connected with the eye tracking device compares a user&#39;s gaze information with information displayed on the portable device display at the time of the user&#39;s gaze. This gaze information may be linked to an item displayed on the display at the location of the user&#39;s gaze and stored. This stored information may then be used by an application stored on the portable device. In this way, the context of the information gazed at by a user may be used by multiple applications on the portable device. For example, a user may gaze at a location on a map displayed on the display, then when the user accesses another application, such as a web browser, that location may be used to display customized results. 
     As a further example, a user may gaze at information on the display and that information may be temporarily stored by the portable device and provided to applications on the portable device. This is best illustrated by the case where a user views a timetable on their device, such as a bus timetable. If the user then loads an application to transmit information about the bus times, such as a messaging application, according to the present invention the time of the last viewed bus, or the time of the bus that was most often viewed, can be automatically provided to the messaging application. This same invention can be applied to many use cases, for example images can be inserted into messages or emails based on the user&#39;s gaze history or a user looking at recipes, shopping lists etc can have their viewed at information provided to shopping applications or web browsers, so as to expedite the process of searching of the items in the shopping list, recipe etc. 
     As a further example, a user may have recently installed a new application on their portable device. Upon first use, a certain number of uses, until disabled by the user, or always, the application may provide visual information to the user dependent upon their gaze location. For example, if the application was a mail application, when the user gazed at an icon that provides the ability to write new mail messages, the icon may visually highlight via a change in color, position, size etc. 
     As a further example, a user may be utilizing an application that offers extended functionality. For example, a map application may show nearby restaurants if a menu is enabled. By utilizing gaze information, an indication of this extended functionality may be offered to the user. For example, in a map application the nearby restaurants information may normally be identified by “swiping” (moving ones finger across the display) from the side of the display. By utilizing gaze information, when the user looks at his location on the map, the extended functionality may slightly appear from the side of the display, demonstrating to the user that more functionality may be achieved by swiping from that side of the display. 
     To sum up, this embodiment of the present invention can be described in the following manner:
         An item is displayed on a display on a portable device.   An eye tracking device determines a user&#39;s gaze relative to the display.   The portable device determines that a user&#39;s gaze is, or was, located on or near the item. Based on the duration of the gaze on the item, the portable device can determine that the user is:
           Glancing at the item, in which case the portable device will take no action.   Interested in the item, in which case the portable device can respond by taking a first action.   Very interested in the item, in which case the portable device can respond by taking a second action.   
               

     To demonstrate, consider the following use cases:
         The item is an image of a button, the first action is visually highlighting the button, and the second action is providing a visual hint as to the effect of activating the button.   The item is a reduced resolution version of an image (aka a thumbnail), the first action is visually highlighting the thumbnail, and the second action is enlarging the thumbnail.       

     The determination of whether the user is interested or very interested can be based on total time the user gazes at the item, where once the user has gazed at the icon for a predetermined length of time, the device determines the user is interested or very interested. Alternatively, the determination could similarly be based on frequency of times the user gazes at the item. Alternatively, the determination could be based on the history of the user&#39;s usage of the portable device. 
     Embodiments Involving User Presence 
     According to a further embodiment of the present invention there is provided a system and method for adapting the interface of a portable device based on information derived from a user&#39;s gaze. The system comprises a portable device containing, or operatively linked to, an eye tracking device, where the eye tracking device is adapted to determine a user&#39;s gaze relative to the portable device. Preferably the portable device contains a display, and a module for displaying information on that display. This module is typically part of an operating system. Popular operating systems include the Google Android™ and Apple iOS™ operating systems. A module in the portable device operatively connected with the eye tracking device compares a user&#39;s gaze information with information displayed on the portable device display at the time of the user&#39;s gaze. This gaze information may be linked to an item displayed on the display at the location of the user&#39;s gaze and stored. This stored information may then be used by an application stored on the portable device. This information may be used, for example, to determine that user is facing the display and therefore power saving features such as dimming of the display may not occur. Further, for example, sound emitted by the device either universally or for a specifics application or specific period, may be muted or otherwise reduced in volume while a user is facing or looking at the display. 
     The presence of a user, or the gaze of a user, may be used to modify the contents of the display, or behavior of the portable device. For example, an application may be provided on a portable device allowing a user to set a timer, in other words a countdown from a numerical value to zero. When the timer reaches zero, typically an alarm will sound to notify the user that the timer has reached zero. According to one embodiment of the present invention, the alarm may be silenced when the user gazes at the portable device. Alternatively, the mere presence of the user&#39;s face near the portable device may cause the alarm to silence. 
     Determination of the user&#39;s presence may be initiated by the portable device indicating it is in an active mode, which could be triggered by an accelerometer, specific application running on the device etc. Once the user&#39;s presence has been established, functionality on the device may be altered accordingly. 
     For example, the display may increase or decrease in brightness, audio may increase or decrease in volume, text may be obscured or revealed, the order of items on the display may be changed etc. 
     In order to demonstrate, consider an example where a portable device is receiving a phone call. The device may emit a ring tone, without powering on the display until a user&#39;s presence is detected. The device could then determine that either the user has been present for a predetermined period of time, or the user has gazed at certain information (such as the caller identification), and decrease or mute the volume of the ring tone. 
     Presence based information could also be modified based on the identity of the user, if the user has been identified. For example, the identity of the user could determine how much information is displayed. Take a text message for example, an unidentified user may not be able to read the contents of the message, while an identified user may. 
     Embodiments Involving Providing Feedback to the User 
     According to a further embodiment of the present invention there is provided a system and method for adapting the interface of a portable device based on information derived from a user&#39;s gaze. The system comprises a portable device containing, or operatively linked to, an eye tracking device, where the eye tracking device is adapted to determine a user&#39;s gaze relative to the portable device. Preferably the portable device contains a display, and a module for displaying information on that display. This module is typically part of an operating system. Popular operating systems include the Google Android™ and Apple iOS™ operating systems. A module in the portable device operatively connected with the eye tracking device compares a user&#39;s gaze information with information displayed on the portable device display at the time of the user&#39;s gaze. This gaze information may be linked to an item displayed on the display at the location of the user&#39;s gaze and stored. This stored information may then be used by an application stored on the portable device. For example, the information may be used to highlight, or otherwise visually mark items on a display to draw a user&#39;s attention. For example, it is typical in the operating system of a portable device to allow for many applications to be loaded and run on the device. It can be difficult for a user to understand which applications may be interacted with, or within an application, which sections, icons etc may be interacted with. Through the utilization of gaze information, according to the present invention, elements on the display may demonstrate that they may be interacted with, or even how they may be interacted with, when a user gazes at the element. This demonstration includes, but is not limited to, changing of color, size, displaying new colors, animations, and changing images. 
     Embodiments Involving Transitioning Between Visual Indications 
     As shown in  FIG. 25 , when a portable device displays a visual indication based on gaze such as a highlight, animation etc. as has been previously described, and the gaze signal is momentarily lost, it is beneficial to have a soft transition so as to minimize the effect of the lost signal on the user. 
     Take for example a visual indication being a highlighting of an icon on the display, if the visual indication is a hard on/off style transition, then when the gaze signal is momentarily lost, the highlight will immediately cease. This creates an abrupt experience for the user. If the highlight appears in a transitional manner, as shown in  FIG. 25  where the amount of highlight increases gradually, then when the gaze signal is momentarily lost, the highlight beings to gradually decrease. If the gaze signal is resumed, the highlight may gradually increase again. This creates an easier, more natural experience for the user. 
     Embodiments Involving Locking Focus of an Action 
     According to one embodiment of the present invention, a user&#39;s gaze information is used to determine an item on a display in which the user wishes to interact. This determination could be based on gaze duration, frequency of gaze, gaze history or any other metric described in this application. 
     Once the item of focus by the user has been determined, interaction with that item can continue even if the user gazes away from the item. Interaction could be touch based, gesture based, voice based or any other form of interaction conceivable. The interaction with the item ceases when the interaction itself ceases. 
     For example, a user may gaze at an icon on a display which controls a dimmable light in a room. The level of brightness of the light may be adjusted by sliding a finger across the display. According to this embodiment of the present invention, the user gazes at the icon, then places their finger on the display and moves their finger to control the brightness. Regardless of the location of the user&#39;s gaze during the sliding gesture, operation of the light switch will not be interrupted. Once the sliding gesture is complete and the user&#39;s finger is removed from the display, normal operation of the device resumes. 
     Embodiments Using Gaze and Non-Gaze Input 
     According to one embodiment of the present invention, the subject of a user&#39;s gaze may be combined with a non-gaze input to provide functionality on a portable device. For example a user may gaze at an item on a display and speak a specific word, the portable device may then execute a function based on the spoken word and the item gazed at on the display. To demonstrate, a user may gaze at a list of contacts on a display and linger their gaze on a specific contact. The user may then say “call” for example, and the portable device will call the phone number associated with the contact the user&#39;s gaze is lingering on. 
     Over time, the user&#39;s gaze information may be collected to improve the accuracy of the non-gaze input. For example, frequently gazed at information on a display can be more readily used by non-gaze input enabled applications. This may be used by predictive text algorithms, as would be readily understood by a person skilled in the art. Frequently gazed at words, phrases or letters may be collected and used to predict text that is being typed by a user. 
     In a further improvement, the context of the non-gaze input may be modified by the location of a user&#39;s gaze. For example, the user may gaze at a text field in an internet search engine, and when the user speaks a word, the search engine may search for results relevant to that world. Whereas if the user was to speak that same word while the user was gazing elsewhere than the text field, then a different function or possibly no function would be executed. 
     Embodiments Involving Avatars 
     According to one embodiment of the present invention, the information displayed on a display may be in the form of an avatar. An avatar is a graphical representation of a person, animal, or any other such being. By displaying an avatar, a portable device may provide a more personable experience to a user. 
     According to the present invention, a user&#39;s gaze may be determined and once recognized by the portable device that a user&#39;s gaze is directed towards or near a displayed avatar, the avatar may respond in some fashion. The response of the avatar includes, but is not limited to:
         Following a user&#39;s gaze direction with the eyes of the avatar.   Allowing for voice control from the user towards the avatar.   Emitting a sound or voice to the user.       

     In this manner, a user may interact with a portable device using their voice only when they intend. Without gaze being determined to be towards or near the avatar, the portable device will not analyze the user&#39;s voice for spoken commands. However, certain commands may still be spoken towards the portable device without the user&#39;s gaze direction being detected towards the display. For example, a spoken command such as “where are you?” may still cause the portable device to respond. 
     Embodiments Involving Text Input 
     According to another embodiment of the present invention, improved input to a portable device using a touch based keyboard is proposed. This embodiment allows a user to conveniently enter text into a portable device without requiring stretching of fingers across the portable device to select a text input field. 
     The information displayed on the display comprises a text input field, when a user&#39;s gaze is determined by the portable device to be direct to or near the text input field, a keyboard is displayed on the screen. Alternatively the user may contact the device with a finger to enable the display of the keyboard, this may be a touch or swiping motion by the user. This contact may occur on the display, on a physical button or outside of the portable device. 
     Once the keyboard is displayed on the screen, the user may enter text into the text input field in a manner as would be recognized by anyone of skill in the art, in fact by anyone who has ever used a portable device with a touch interface. 
     Embodiments Involving Click at Gaze 
     According to another embodiment of the present invention, the information displayed on the display is icons or other such information that may be selected by a user. 
     Once the portable device determines that the user&#39;s gaze is directed towards a predetermined area of the display, such as the top, icons may be enlarged. By then gazing at an enlarged icon it may be selected by pressing on the portable device in some fashion. 
     Alternatively, the enlargement of icons may be performed upon a touch input such as placing a finger on the screen in a predetermined area, or on a fingerprint sensor of the like. Upon enlargement, gaze may be used to determine which icon is to be selected and when the user removes their finger from the screen or fingerprint sensor, or performs a deliberate action such as swiping, clicking or the like, an application associated with the selected icon may be opened. 
     In a further improvement, enlargement may be optional and fine adjusting of the gaze direction can be performed through contact with the display or a fingerprint sensor. In other words, a user&#39;s gaze direction may be shown on the display, or an icon highlighted, and by moving a finger on the screen or sensor this direction or highlight may be moved proportionally. 
     Optionally, interaction such as a click with the portable device may be achieved by touching any location on the portable device and gazing at the subject of the action on the display. This touch may be in a predetermined area on the display, or be performed in a certain manner, for example 2 touches in quick succession. 
     Optionally, in place of icons being enlarged, icons showing currently running processes and applications may be displayed upon a user&#39;s gaze being directed towards a predetermined area of the screen. The user may then gaze towards an icon representing a currently running application the user desires to activate, upon dwelling their gaze upon the icon or contacting the portable device in a predetermined manner, the selected application may be made active on the portable device. 
     Embodiments Involving Lock Screens 
     In another embodiment of the present invention, information may be displayed on the display during a “locked” or limited functionality phase of the portable device. Typically such a phase is used to show notifications such as missed calls, messages, reminders and the like. 
     By determining gaze direction in such a phase, certain notifications or other items on the display may be highlighted. Highlighting may include brightening of the notification, otherwise graphically separating the notification from other items on the display, or displaying further information regarding the notification. 
     Selecting a notification may be performed by touching the display or a fingerprint sensor, or by dwelling gaze on the notification for a predetermined period of time, for example 0.1 to 5 seconds. 
     Further, by maintaining contact with a fingerprint sensor or the like, separate notifications may expand and/or separate, allowing for easier gaze determination towards each notification. Upon gazing at a notification, more information regarding that notification may be displayed. For example if the notification is a text message, the name of the person from which the text message may be initially displayed, and then the entire text message displayed in an expanded view. By releasing the fingerprint sensor while gazing at a notification, the fingerprint sensor may recognize a user&#39;s fingerprint and unlock the portable device and open an application associated with the notification. 
     Further, if a notification is gazed at for a predetermined period of time, for example 1 to 5 seconds. The portable device may cease to display the notification. 
     The above innovations regarding notifications are described with reference to notification displayed when a portable device is in a locked state, however they apply equally to notifications displayed with the portable device is in an unlocked state. 
     Embodiments Involving Audio Adjustment 
     In another embodiment of the present invention, there is provided a method for lowering an audible sound from a portable device (for example, music, video sound, ring tones, alerts, warnings, etc.), upon a user&#39;s gaze or eyes being detected. The embodiment functions in the following manner: 
     1. The portable device emits a sound. 
     2. An eye determination portion of the portable device (i.e., an eye tracking device or other image sensor (i.e., camera or other image/video capture device) determines that a user is gazing towards the portable device. 
     3. The volume of the sound emitted by the portable device decreases. 
     The volume decrease described in step 3 may be a gradual decrease, or an instantaneous decrease—otherwise known “mute.” The decrease may be total (volume to zero), or may be to a predetermined lower level (either an absolute level or a percentage level relative to the original volume). In some embodiments, a difference audio content (e.g., a notification of gaze recognition and/or dismissal of the original audio content) could be delivered upon determination that the user&#39;s gaze has shifted to or near the device. A choice of the preferred method of audio change, along with its associated parameters, may be determined by a user and stored within the portable device, for use during step 2. 
     The determination of a user&#39;s gaze in step 2 may be based on a determination that a user has gazed anywhere within the vicinity of the portable device (for example, within five centimeters of the device), or upon a specific, predetermined area of the portable device (for example, the screen, keyboard, and/or a particular side of the portable device). 
     Further, the determination may not be based upon gaze at all, but rather upon a determination that an image sensor in the portable device (i.e., camera or other image/video capture device) has captured an image containing at least one of a user&#39;s eyes. 
     Examples of suitable sounds that may be altered by this embodiment are ringtones of a portable device as well as an alarm emitted by a portable device. 
     Turning to  FIG. 24 , the above method  2400  of the invention is shown in block diagram form. At block  2410 , it is determined whether the portable device is emitting audio content. If so, method  2400  recognizes that such audio content may change should a particular gaze event occur (i.e., particular eye information such as gaze direction, eye presence, and/or eye position). At block  2420 , it is determined whether a gaze event has occurred. As discussed above, this could result from the mere detection of an eye of the user, or of a particular gaze direction of the user. At block  2430 , the audio content is changed based on the gaze event. 
     Embodiments Involving Off Screen Menus 
     In another embodiment of the present invention, there is provided a method for accessing menus and the like on a portable device through the use of gaze directed away from the device. The embodiment functions in the following manner: 
     1. Determine a user&#39;s gaze is outside a portable device 
     2. Detect a movement of the portable device in a defined direction 
     3. Display a menu or perform an action on the portable device, based on the direction of movement in step 2. 
     Alternatively to step 2, a gesture such as a swipe may be performed on a touch-sensitive surface of the portable device. 
     In the above manner, a user may perceive the sensation of “pulling in” something located off screen. For example the user may gaze above the portable device, while simultaneously pulling the phone in a downwards motion, causing a menu to appear on the display from the top of the portable device. This gives the user a feeling of looking at an invisible menu that exists above the portable device, and then pulling that menu in by moving the device downwards. 
     Embodiments Involving Device Activation 
     According to another embodiment of the present invention a method is provided for activating a portable device and enabling gaze tracking. The method comprises the following steps: 
     1. Place a portable device in an inactive mode. 
     2. Receive an activation signal for the portable device. 
     3. Switch the portable device to active mode. 
     4. Enable gaze tracking 
     Step 2 may be achieved by shaking or touching the portable device in a predetermined manner. 
     By way of example, the present embodiment may function in the following manner. A portable device is programmed to switch to a battery saving inactive mode after a certain period of time where the device is not used, for example the screen may be switched off. In this inactive mode, any hardware and software used for gaze tracking is typically disabled. Upon shaking the portable device, the portable device is switched to active mode and the gaze tracking hardware and software is enabled. 
     Embodiments Involving Hands Free Answering 
     In another embodiment of the present invention, there is provided a method for answering a telephone call received by a portable device. In this method the following steps are followed: 
     1. A portable device receives a telephone call. 
     2. The portable device notifies a user of the call through a visual representation. 
     3. The user gazes at the visual representation, and the portable device recognizes the gaze as being directed on or around the visual representation. 
     4. The portable device answers the call and immediately places the portable device into “handsfree” mode. 
     “Handsfree mode” is intended to refer to a commonly known method of handling telephone calls on portable devices, whereby a microphone and speaker in the portable device are operated such that a user can participate in a telephone call without physically contacting the portable device. A handsfree mode may also be used with external devices such as a headset, external speakers and/or external microphones. 
     The visual representation in step 2 is preferably an icon or image representing answering a telephone call, for example a green image of a telephone may be used. 
     In a further improvement on this embodiment whereby the device need only determine a user&#39;s eye position, if the device determines that a user performs a “nodding” motion with their head upon a telephone call being received, the device may answer the call and enter handsfree mode. Alternatively, if the device determines the user is performing a “shaking” motion with their head, the device may refuse the call. 
     Embodiments Involving a Portable Device as an Information Device 
     According to another embodiment of the present invention, a portable device may be used to display information pertinent to the surrounds of the device, based on a gaze direction of a user. 
     In this embodiment, the following steps are performed: 
     1. A portable device determines a user&#39;s gaze direction relative to the portable device. 
     2. The portable device determines positional information of the portable device. 
     3. If the user&#39;s gaze direction is directed outside the portable device, the portable device receives information relevant to the subject of the user&#39;s gaze direction. 
     4. The portable device displays such information. 
     Step 2 of this method requires that the portable device determine positional information, this may be utilizing a global positioning system receiver (GPS), accelerometer, gyroscope or similar or a combination thereof. 
     Step 3 of this method requires that the portable device receive information relevant to the subject of the user&#39;s gaze, optionally this information may already be stored in the portable device and instead of receiving the information, the portable device retrieves the information from memory. 
     The information may be directed to the portable device through multiple methods, including:
         The portable device may utilize a GPS system to determine its location, and download suitable information.   The portable device may receive information from a nearby transmitter.       

     To illustrate this embodiment of the present invention, the following example is provided. A user may use a portable device in an environment such as a museum, the portable device may have stored information relevant to exhibits in the museum along with positional information of the exhibits. As a user moves around the museum, the portable device determines that the user&#39;s gaze is directed away from the portable device. Using the positional information of the device, the portable device can determine exhibits located close to it, as well as which exhibit the user is gazing towards. Thus the portable device can display information relative to that exhibit. 
     Embodiments Involving Page Flipping 
     According to another embodiment of the present invention, there is provided a method for moving from one page to another in a book or similar displayed on a portable device. This embodiment functions with only the determination of eye position of the user. The method functions with the following steps: 
     1. Display a first page of a multi-page document. 
     2. Determine that a user&#39;s eye position is indicative of a tilted head. 
     3. Display or emit an indicator that the next or previous page of the multi-page document is about to be displayed. 
     4. If the user&#39;s eye position remains substantially the same, display the next or previous page, otherwise do not display the next or previous page. 
     Determination of the user&#39;s eye position may be performed using any image sensor of the device. The position may be compared to a “normal” position whereby a user&#39;s eye or eyes is in a substantially horizontal position. The orientation of the user&#39;s eyes is used to determination in which direction to turn the pages of the multipage document. For example, if the orientation is such that the user has tilted their head to the right, the next page will be displayed and vice-versa. 
     Alternatively the device may skip displayed pages, for example if the user continues to tilt their head, multiple pages may be passed over until the user straightens their head. 
     The visual indicator described in step 3 is preferably an animation of a page turning, but may be any form of image, video, sound or the like. 
     Embodiments Involving View Change by Distance 
     According to another embodiment of the present invention, a display is changed on a portable device according to the distance of the device from a user. The embodiment contains the following steps: 
     1. Enable a mode on a portable device having a plurality of views or components. 
     2. Determine that a user is present in front of the device using an image sensor. 
     3. Determine that the device is moving. 
     4. Alter the view or component of the mode on the display based on the movement of the device. 
     5. Cease to alter the display when the movement of the device stops. 
     The movement of the device may be forward-backwards or side to side. By way of example, on a portable device containing many menus of items, the device may be held in front of a user and moved backwards until the desired menu of items is reached. 
     Further, the embodiment may function in the opposite manner whereby when a user moves his/her head relative to the device, the displayed information changes. In this manner the device determines a user&#39;s eye position and tracks any relative changes in the eye position, if it determines that the eye position indicates the user is closer or further away from the device, information on the display is changed. For example if the device is displaying a map, and it determines that the user is moving his/her head towards the map, the device may display a zoomed in/enlarged view of a portion of the map. 
     Embodiments Involving Power Saving 
     According to another embodiment of the present invention, the GPS of a portable device may only be activated when the portable device determine that a user is present in front of the device. The determination of a user&#39;s presence is performed by analyzing an image captured by an image sensor on the device, whereby the analysis looks for the presence of a user&#39;s eye or eyes. 
     Further, if the device determines it is not in a position to perform eye tracking, eye position determination or presence determination it may disable any image sensors or associated hardware or software. For example, the device may determine by the proximity of a user&#39;s eyes that the user is too close to the display to accurately perform eye tracking or eye position determination. The device may also determine, through information obtained by capturing images with the image sensor, that the device is upside down, on a surface, in a pocket etc. 
     For any of the aforementioned embodiments, further sensors found in the portable device may be used to complement information obtained by a gaze tracking or eye position determination system. For example, if the device contains an accelerometer, information from the accelerometer may be used to determine if the device has moved and this information can be compared to information from the eye tracking or eye position determination system to decide if the device has moved, or the user&#39;s head has moved. 
     While operations are depicted in the drawings in a particular order, this should not be understood as require such operations be performed in the particular order shown or in sequential order, or that all illustrated operation be performed to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementation described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. 
     Additional Embodiments 
     In some embodiments, a user&#39;s attention level to a particular display or other stimuli application may be classified as falling within one or more of a particular number of categories. Merely by way of example, three possible attention levels may be defined as “no-attention,” “facing,” or “looking-at.” “No-attention” may occur when a gaze detection system determines that no user is present (i.e., there are no eyes to track). “Facing” may occur when a gaze detection system determines that a user is at least present and their gaze is at least facing the device (i.e., eyes are visible to the gaze detection system). “Looking-at” may occur when a gaze detection system determines that a gaze is more particular detected in some predefined region (or the entirety) of a display. 
     In some embodiments, a given hardware component or displayed graphical component may also be classified as falling within one or more of a particular number of categories regarding the user&#39;s attention thereto. Merely by way of example, six possible attention levels may be defined as “unobserved,” “faced,” “glanced-at,” “viewed,” “seen,” and “interesting-to-user.” “Unobserved” may be established as a component status when a gaze detection system determines that the component has not yet been looked at by a user (i.e., the eyes of the user have not been detected). “Faced” may be established as a component status when a gaze detection system determines that the component has not yet been looked at by a user, but the user is generally facing the component (i.e., eyes detected, but not gaze on the component). “Glanced-at” may be established as a component status when a gaze detection system determines that the component has been gazed at by the user for at least some minimum threshold of time, but not longer than some maximum threshold of time. “Viewed” may be established as a component status when a gaze detection system determines that the component has been gazed at by the user for at least some minimum threshold of time (i.e., longer than “glanced-at”). 
     “Seen” may be a highly contextual status which is established as a component status when a gaze detection system determines that the user&#39;s gaze has interacted with the component in at least a certain manner, which may vary depending on the content of the component). Merely by way of example, various factors, depending on the content of the component, may be examined such as the amount of time the user&#39;s gaze has remained or revisited the component, the pattern of the gaze (i.e., direction it moves to, and around, the component), etc. An elevated version of the “seen” status may be “interesting-to-user” and may rely on similar factors, but require a greater magnitude of agreement therewith. 
     Taking into account the above user attention levels and component statuses may allow for more useful interactions and/or smarter predictions about user intentions and/or needs. The user attention levels and component statuses may thus supplement any other gaze detection efforts and algorithms discussed herein or elsewhere. This may especially be the case in mobile-device applications, where traditional input systems are either limited or not present (i.e., full size keyboards, and mice). But such methods discussed herein can also at least supplement tradition input systems regardless. Finally, face identification via gaze detection systems may also supplement or replace other identification verification systems at the same time. 
     Merely by way of example, one possible interaction with a mobile or other device which may be improved is by input prediction. If a user is regularly observed gazing at photos of certain objects, the name of that object may be more likely to appear in a typing interface where words are suggested to the user as they type. For example, a touch keyboard application or a search prompt may suggest the name of the object as a possible input. Context of the current situation (e.g., other nearby words and/or the particular application being used) may be used by the algorithm to further predict precisely when such a suggested input would be necessary. 
     Another possible interaction is where sorting of various items can occur based on previous gaze patterns. For example, a list of applications, documents, or media files may be sorted based on previous viewing patterns, with often looked at items being placed higher or to one end in a list or arrangement than less often looked at items. 
     In some embodiments, gaze inputs may be used to supplement other input modes and/or other applications from which the gaze data is received to increase later input accuracy. Merely by way of example, names of often gazed at items could be added to speech recognition input means, and or narrow search results quickly. Preferences for operating system and/or application elements could also be based at least partially on gaze detection information. Likewise, recipients for transmitted information could also, over time, be associated with particular gaze patterns of a user, as well as particular content gazed at by the user. 
     In some embodiments, components that have been seen by a user for minimum amounts of time may be hidden or otherwise reduced from prominent view. This functionality may be particularly useful on lock screens and other notification screens on mobile devices. 
     In some embodiments, transient graphical components may only be displayed for default time periods to a user before disappearing or otherwise being minimized. For example, email clients may display “toast” or other notifications which will remain for a set period of time on the display before being removed or minimized. Embodiments herein may determine that a user is gazing upon such notifications, and extend, either for a predefined period of time, or indefinitely, display of the notification. Any time-dependent sleep or lock modes of an application/device may also be extended in this manner, such that sleep/lock modes are delayed so long as user gaze is detected. 
     In some embodiments, facial recognition via a gaze-detection or other system may allow for a user&#39;s identity to be continually verified. So long as verification occurs, access to security-sensitive applications may continue, but end when facial recognition is no longer possible. This may allow for automatic login and/o shutdown of security sensitive applications when a user begins/stops observing the application. Likewise, a guest mode may be available for an application or device which provides a different interface for the owner or regular user of the device than that which may be provided to a guest, based on who the gaze detection system believes is using the device. 
     In some embodiments, gaze requirements may be set for data which is transmitted between parties so that only certain intended recipients of the data can retrieve the information. Merely by way of example, facial, iris, or some other facial identification may be required for a transmitted message to be opened or readable. 
     In some time sensitive applications, an application may inform a user graphically or otherwise of changes that have occurred since a component was previously viewed. This may allow a user to quickly understand what changes have occurred since a prior viewing. 
     In another embodiment, gaze information may be transmitted to other parties to enhance communication there-between. For example, if two users are viewing a textual conversation on different devices, each person may be informed in some manner of what portion of the conversation is being observed by the other person.