# Patent

## Title
Combining explicit select gestures and timeclick in a non-tactile three dimensional user interface

## Abstract

A method including presenting, by a computer, multiple interactive items on a display coupled to the computer, and receiving, from a depth sensor, a sequence of three-dimensional (3D) maps containing at least a hand of a user of the computer. An explicit select gesture performed by the user toward one of the interactive items is detected in the maps, and the one of the interactive items is selected responsively to the explicit select gesture. Subsequent to selecting the one of the interactive items, a TimeClick functionality is actuated for subsequent interactive item selections to be made by the user.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application 61/523,404 filed on Aug. 15, 2011, and of U.S. Provisional Patent Application 61/526,692 filed on Aug. 24, 2011, which are both incorporated herein by reference.


FIELD OF THE INVENTION
This invention relates generally to user interfaces for computerized systems, and specifically to user interfaces that are based on three-dimensional sensing.
BACKGROUND OF THE INVENTION
Many different types of user interface devices and methods are currently available. Common tactile interface devices include the computer keyboard, mouse and joystick. Touch screens detect the presence and location of a touch by a finger or other object within the display area. Infrared remote controls are widely used, and “wearable” hardware devices have been developed, as well, for purposes of remote control.
Computer interfaces based on three-dimensional (3D) sensing of parts of the user's body have also been proposed. For example, PCT International Publication WO 03/071410, whose disclosure is incorporated herein by reference, describes a gesture recognition system using depth-perceptive sensors. A 3D sensor provides position information, which is used to identify gestures created by a body part of interest. The gestures are recognized based on a shape of a body part and its position and orientation over an interval. The gesture is classified for determining an input into a related electronic device.
As another example, U.S. Pat. No. 7,348,963, whose disclosure is incorporated herein by reference, describes an interactive video display system, in which a display screen displays a visual image, and a camera captures 3D information regarding an object in an interactive area located in front of the display screen. A computer system directs the display screen to change the visual image in response to changes in the object.
Documents incorporated by reference in the present patent application are to be considered an integral part of the application except that to the extent any terms are defined in these incorporated documents in a manner that conflicts with the definitions made explicitly or implicitly in the present specification, only the definitions in the present specification should be considered.
The description above is presented as a general overview of related art in this field and should not be construed as an admission that any of the information it contains constitutes prior art against the present patent application.
SUMMARY OF THE INVENTION
There is provided, in accordance with an embodiment of the present invention a method including presenting, by a computer, multiple interactive items on a display coupled to the computer, receiving, from a depth sensor, a sequence of three-dimensional (3D) maps containing at least a hand of a user of the computer, detecting, in the maps, an explicit select gesture performed by the user toward one of the interactive items, selecting the one of the interactive items responsively to the explicit select gesture, and actuating, subsequent to selecting the one of the interactive items, a TimeClick functionality for subsequent interactive item selections to be made by the user.
There is also provided, in accordance with an embodiment of the present invention an apparatus including a depth sensor, and a computer executing a non-tactile three dimensional (3D) user interface and configured to present, multiple interactive items on a display coupled to the computer, to receive, from the depth sensor, a sequence of three-dimensional (3D) maps containing at least a hand of a user of the computer, to detect, in the maps, an explicit select gesture performed by the user toward one of the interactive items, to select the one of the interactive items responsively to the explicit select gesture, and to actuate, subsequent to selecting the one of the interactive items, a TimeClick functionality for subsequent interactive item selections to be made by the user
There is additionally provided, in accordance with an embodiment of the present invention a computer software product including a non-transitory computer-readable medium, in which program instructions are stored, which instructions, when read by a computer, cause the computer to present multiple interactive items on a display coupled to the computer, to receive, from a depth sensor, a sequence of three-dimensional (3D) maps containing at least a hand of a user of the computer, to detect, in the maps, an explicit select gesture performed by the user toward one of the interactive items, to select the one of the interactive items responsively to the explicit select gesture, and to actuate, subsequent to selecting the one of the interactive items, a TimeClick functionality for subsequent interactive item selections to be made by the user.



BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure is herein described, by way of example only, with reference to the accompanying drawings, wherein:
FIG. 1 is a schematic, pictorial illustration of a computer system implementing a non-tactile three dimensional (3D) user interface, in accordance with an embodiment of the present invention;
FIG. 2 is a schematic, pictorial illustration showing visualization and interaction regions associated with the non-tactile 3D user interface, in accordance with an embodiment of the present invention;
FIG. 3 is a flow diagram that schematically illustrates a method of activating TimeClick functionality, in accordance with an embodiment of the present invention.
FIG. 4 is a schematic pictorial illustration of an on-screen keyboard for use with the non-tactile 3D user interface, in accordance with an embodiment of the present invention;
FIG. 5 is a state diagram that schematically illustrates states and transitions of the computer executing the non-tactile 3D user interface, in accordance with an embodiment of the present invention.
FIGS. 6A and 6B are schematic pictorial illustrations of the computer presenting a flashlight cursor, in accordance with an embodiment of the present invention; and
FIG. 7 is a state diagram that schematically illustrates states and transitions of the computer implementing the flashlight cursor, in accordance with an embodiment of the present invention.



DETAILED DESCRIPTION OF EMBODIMENTS
When using a tactile input device such as a mouse, the user typically manipulates the physical device in a two-dimensional plane comprising a horizontal X-axis and a vertical Y-axis. However, when interacting with a non-tactile 3D user interface (also referred to herein as a 3D user interface), the user may perform gestures in mid-air, and perform the gestures from different positions within a field of view of a 3D sensor coupled to the interface.
While interacting with a non-tactile 3D user interface, a user can perform a Find gesture in order to highlight (e.g., via a cursor) a given interactive item presented on a display, and then select the highlighted item by performing an explicit select gesture with a part of the user's body such as a hand. Examples of explicit select gestures described hereinbelow include Push, Pull and Grab gestures. In addition to performing the explicit select gestures described herein, the user can select the highlighted interactive item via TimeClick (also referred to herein as a TimeClick gesture). To select a highlighted item via TimeClick, the user keeps his hand relatively steady so that the given interactive item is highlighted for a specific period of time by user 22. The specific period is also referred to herein as the hold-time.
Embodiments of the present invention provide methods and systems for combining explicit select gestures and TimeClick in a non-tactile 3D user interface. In some embodiments, a computer may present multiple interactive items on a display, and upon the user selecting a first interactive item using an explicit select gesture, the computer activates a TimeClick engaged mode, wherein subsequent items can be selected using TimeClick. In an alternative embodiment, the computer may present a TimeClick icon (i.e., a mode key) on the display, and upon the user performing an explicit select gesture to select the TimeClick icon, the 3D user interface activates the TimeClick engaged mode.
System Description
FIG. 1 is a schematic, pictorial illustration of a non-tactile three dimensional (3D) user interface 20 for operation by a user 22 of a computer 26, in accordance with an embodiment of the present invention. The 3D user interface is based on a 3D sensing device 24 (also referred to herein as a depth sensor) coupled to the computer, which captures 3D scene information of a scene that includes the body (or at least a body part, such as one or more of hands 30) of the user. Device 24 or a separate camera (not shown in the figures) may also capture video images of the scene. The information captured by device 24 is processed by computer 26, which drives a display 28 so as to present and manipulate on-screen interactive items 38. Details of the operation of 3D sensing device 24 are described in U.S. Patent Application 2010/0007717, filed on Mar. 4, 2009, whose disclosure is incorporated herein by reference.
Computer 26, executing 3D user interface 20, processes data generated by device 24 in order to reconstruct a 3D map of user 22. The term “3D map” refers to a set of 3D coordinates measured, by way of example, with reference to a generally horizontal X-axis 32 in space, a generally vertical Y-axis 34 in space and a depth Z-axis 36 in space, based on device 24. The 3D coordinates represent the surface of a given object, in this case the user's body. In one embodiment, device 24 projects a pattern of spots onto the object and captures an image of the projected pattern. Computer 26 then computes the 3D coordinates of points on the surface of the user's body by triangulation, based on transverse shifts of the spots in the pattern. Methods and devices for this sort of triangulation-based 3D mapping using a projected pattern are described, for example, in PCT International Publications WO 2007/043036, WO 2007/105205 and WO 2008/120217, whose disclosures are incorporated herein by reference. Alternatively, interface 20 may use other methods of 3D mapping, using single or multiple cameras or other types of sensors, as are known in the art.
Computer 26 typically comprises a general-purpose computer processor, which is programmed in software to carry out the functions described hereinbelow. The software may be downloaded to the processor in electronic form, over a network, for example, or it may alternatively be provided on non-transitory tangible media, such as optical, magnetic, or electronic memory media. Alternatively or additionally, some or all of the functions of the image processor may be implemented in dedicated hardware, such as a custom or semi-custom integrated circuit or a programmable digital signal processor (DSP). Although computer 26 is shown in FIG. 1, by way of example, as a separate unit from sensing device 24, some or all of the processing functions of the computer may be performed by suitable dedicated circuitry within the housing of the sensing device or otherwise associated with the sensing device.
As another alternative, these processing functions may be carried out by a suitable processor that is integrated with display 28 (in a television set, for example) or with any other suitable sort of computerized device, such as a game console or media player. The sensing functions of device 24 may likewise be integrated into the computer or other computerized apparatus that is to be controlled by the sensor output.
Actuating Timeclick Functionality
FIG. 2 is a schematic, pictorial illustration showing how user 22 may interact with visualization and interaction regions associated with 3D user interface 20, in accordance with an embodiment of the present invention. For the purpose of this illustration, an X-Y plane 40 is taken to be parallel to the plane of display screen 28, with distance (depth) perpendicular to this plane corresponding to the Z-axis, and the origin located at device 24. Computer 26 creates a depth map of objects within a field of view 42 of device 24, including the parts of the user's body that are in the field of view.
The operation of 3D user interface 20 is based on an artificial division of the space within field of view 42 into a number of regions:

    
    
        A visualization surface 44 defines the outer limit of a visualization region. Objects beyond this limit (such as the user's head in FIG. 2) are ignored by user interface 20. When a body part of the user is located within the visualization surface, the user interface detects it and provides visual feedback to the user regarding the location of that body part, typically in the form of an image or icon on display screen 28. In FIG. 2, both of the user's hands are in the visualization region.
        An interaction surface 46, which is typically located within the visualization region, defines the outer limit of the interaction region. When a part of the user's body crosses the interaction surface, computer 26 can responsively execute control instructions, as would occur, for instance, if the user made physical contact with an actual touch screen. In this case, however, no physical contact is required to trigger the action. In the example shown in FIG. 2, the user's left hand has crossed the interaction surface and may thus interact with application objects.
    
    


The interaction and visualization surfaces may have any suitable shapes. In some embodiments, the inventors have found spherical surfaces to be convenient, as shown in FIG. 2. In alternative embodiments, one or both of the surfaces may be planar.
Various methods may be used to determine when a body part has crossed interaction surface 46 and where it is located. For simple tasks, static analysis of the 3D locations of points in the depth map of the body part may be sufficient. Alternatively, dynamic, velocity-based detection may provide more timely, reliable results, including prediction of and adaptation to user gestures as they occur. Thus, when a part of the user's body moves toward the interaction surface for a sufficiently long time, it is assumed to be located within the interaction region and may, in turn, result in objects being moved, resized or rotated, or otherwise controlled depending on the motion of the body part.
In operation, upon computer 26 detecting a given hand 30 between visualization surface 44 and display 28, the computer may responsively highlight a given interactive item 38 in response to the given hand's location. In instances where user 22 positions both hands 30 between visualization surface 44 and display 28, computer 26 may select the hand that is closer to the display as the given hand.
If user 22 wants to highlight a different interactive item 38, the user can perform a Find gesture, by moving hand 30 along X-Y plane 40. In some embodiments, computer 26 may highlight a given interactive item 38 by presenting a visual effect. For example, computer 26 can highlight the given interactive item by increasing the brightness of the given interactive item on display 28 or changing the color of the given interactive item. In alternative embodiments (as shown in FIG. 4 hereinbelow), computer 26 may highlight a given interactive item by presenting a cursor in proximity to the given interactive item. The Find gesture is described in U.S. patent application Ser. No. 13/314,207, filed on Dec. 8, 2011, whose disclosure is incorporated herein by reference.
FIG. 3 is a flow diagram that schematically illustrates a method of activating TimeClick functionality (also referred to herein as a TimeClick engaged mode), in accordance with an embodiment of the present invention. In an initial step 50, computer 26 presents multiple interactive items 38 on display 28, and in a definition step 52, the computer defines initial coordinates in space in proximity to the user for interaction surface 46.
In a receive step 54, computer 26 receives, from sensing device 24, a sequence of 3D maps containing at least hand 30, which is positioned within field of view 42. In a detect step 56, computer 26 detects, in the received 3D maps, an explicit select gesture directed toward a given interactive item 38, and in a select step 58, the computer selects the given interactive item responsively to the explicit select gesture. In the disclosure and in the claims, an explicit select gesture is assumed to comprise a movement or series of movements of a body part (typically hand 30) which computer 26 has been programmed to recognize as causing an interaction with the computer.
Examples of explicit select gestures that can be used to select the highlighted interactive item include, but are not limited to Grab, Pull and Push gestures. The Grab, Pull and Push gestures are described in U.S. patent application Ser. No. 13/423,314, filed on Mar. 19, 2012, whose disclosure is incorporated herein by reference. While the explicit select gestures described herein comprise the Grab, Pull and Push gestures, other explicit select gestures performed by hand 30 (or any other body part of user 22), corresponding to the definition hereinabove, are considered to be within the spirit and scope of the present invention.
To select the highlighted interactive item using a Pull gesture, hand 30 is initially positioned between interaction surface 46 and display 28. To perform the Pull gesture, user 22 moves hand 30 away from display, and computer 26 selects the highlighted interactive item upon hand 30 crossing the interactive surface. To perform a Grab gesture user 22 closes at least some fingers of hand 30 (i.e., “grabbing” the item). In some embodiments user 22 can combine a Grab gesture with a Pull gesture (i.e., the user first performs a Grab gesture and then performs a Pull gesture while some fingers of the hand remain closed).
To select the highlighted interactive item using a Push gesture, hand 30 is initially positioned between visualization surface 44 and interaction surface 46. To perform the Push gesture, user 22 moves hand 30 toward display 28, and computer selects the highlighted interactive item upon hand 30 crossing the interactive surface.
Returning to the flow diagram, in a TimeClick step 60, computer 26 switches to a TimeClick engaged mode that actuates TimeClick functionality for subsequent selection of interactive items 38 to be made by the user, and the method ends. Upon entering the TimeClick engaged mode, user 22 can select subsequent interactive items 38 via either an explicit select gesture or TimeClick.
To select a subsequent interactive item using a TimeClick gesture, computer 26 receives a subsequent sequence of 3D maps containing at least hand 30, and detects, in the subsequent sequence of 3D maps, a TimeClick gesture directed at the subsequent interactive item. As explained supra, the TimeClick gesture comprises user 22 keeping hand 30 relatively steady for a specific period of time while computer 26 is highlighting the subsequent interactive item. The specific period of time is also referred to herein as a hold-time or a hold-time parameter.
In some embodiments (i.e., while the TimeClick functionality is actuated), computer 26 can adjust the hold-time parameter in response to a distance between user 22 and sensing device 24. For example, as user 22 moves farther away from 3D sensing device 24, computer 26 can increase the hold-time, since the quality of data collected by the 3D sensing device typically deteriorates as the distance increases between the user and the 3D sensing device.
In some embodiments, selecting a given interactive item 38 comprises executing a software application associated with the given interactive item. In further embodiments the given interactive item is associated with a media item (e.g., a music track or a movie), and selecting a given interactive item 38 comprises playing a media file associated with the given interactive item. In alternative embodiments, computer 26 may present a virtual input device on display 28, and user can interact with the virtual input device using the embodiments described herein. Examples of virtual input devices include but are not limited to on-screen keyboards, keypads and game controls.
FIG. 4 is a schematic pictorial illustration of an on-screen keyboard 70, in accordance with an embodiment of the present invention. In the description of FIG. 4 herein, some of interactive items 38 may be differentiated by appending a letter to the identifying numeral, so that keyboard 70 comprises interactive items 38A-38G.
In the configuration shown in FIG. 4, keyboard 70 comprises alphanumeric keys 38A, a spacebar 38B, an Enter key 38C (also known as a Return key), and a Backspace key 38D. In some embodiments, while interacting with 3D user interface 20, computer 26 positions a hand-shaped cursor 72 on display 28 responsively to user 22 performing a Find gesture. In alternative embodiments (as described supra), computer 26 can highlight a given alphanumeric key 38 in response to the Find gesture. Upon the user selecting one of the alphanumeric keys (i.e., via an explicit select gesture or via TimeClick), computer 26 can present a corresponding alphanumeric character in a text box 74.
For example, to type the word “THE” (as shown in text box 74), user 22 first performs a Find gesture to position cursor 72 over the alphanumeric key “T”, and then performs a Push gesture. Upon presenting “T” in text box 72, computer 26 transitions to the TimeClick engaged mode. To complete typing “THE”, user 22 performs a Find gesture to position cursor 80 over the alphanumeric key “H”, and keeps hand 30 steady until computer 26 accepts the alphanumeric key “H” as input. Finally, user 22 performs a Find gesture to position cursor 80 over the alphanumeric key “E”, and keeps hand 30 steady until computer 26 accepts the alphanumeric key “E” as input. While in TimeClick mode, user 22 may also select alphanumeric keys “H” and “E” using an explicit select gesture such as the Push, the Pull and the Grab gestures described supra.
In some embodiments, while in the TimeClick engaged mode, computer 26 may be configured to alter explicit select gesture parameters. For example, if user 22 can perform a Push gesture to select a highlighted interactive item 38 (e.g., one of the alphanumeric keys) by moving hand 30 forward along Z-axis 36 until the hand crosses interaction surface 46. To enable user to more easily select a highlighted item (e.g., one of alphanumeric keys 38) while in the TimeClick engaged mode, computer 26 may redefine the coordinates of the interaction surface, so that the interaction surface is positioned closer to the user (e.g., so that a closest distance of the interactive surface to a pre-selected portion of user 22 moves from eight inches to four inches.). Likewise, if user 22 is performing a Pull gesture to select the highlighted interactive item while in TimeClick engaged mode, computer 26 may redefine the coordinates of the interaction surface so that the interaction surface is positioned further from the user.
In some embodiments, computer 26 can convey visual feedback to user 22 while the user is selecting a given alphanumeric key using TimeClick. As the example in FIG. 4 shows, in response to user 22 performing a Find gesture, computer 26 positions cursor 72 over the alphanumeric key “X”. As the user keeps hand 30 steady and thereby maintaining the cursor over the alphanumeric key “X” (i.e., before the amount of time specified by the hold-time parameter), the computer can increase shading in the alphanumeric key, or fill a border surrounding the alphanumeric key, or break a border (as shown in the Figure for letters “X” and “I”). Another example of visual feedback, using the letter “T”, is described below.
In some embodiments, while in the TimeClick engaged mode, computer 26 can be configured to adjust the hold-time parameter in response to a proficiency of user 22 as follows:

    
    
        If computer 26 detects that user 22 selected a specified number of alphanumeric keys 38 without selecting backspace key 38D (i.e., without any errors), the computer can shorten the hold-time parameter.
        If computer 26 detects that the user spends less time performing Find gestures while selecting alphanumeric keys 38, the computer can shorten the hold-time parameter. For example, while interacting with on-screen keyboard 70, if the user is spending 50% of the time performing Find gestures and 50% of the time holding the cursor steady to select a given alphanumeric key via TimeClick, the 3D user interface can shorten the hold-time parameter to make text entry less cumbersome (e.g., an optimal breakdown of the time to select a given alphanumeric key 38 may be 90% for the Find gesture and 10% for TimeClick).
    
    


On-screen keyboard 70 may also include a TimeClick timer icon 38F that user 22 can select in order to change the hold-time parameter. For example, a novice user can set the hold-time parameter to a longer time period such as three seconds, while a more experienced user can set the hold-time parameter to a shorter time period such as one second. In operation, computer 26 can adjust the hold-time parameter upon detecting, in a subsequent sequence of 3D maps (i.e., subsequent to the 3D maps received in step 54 hereinabove) a subsequent select gesture (i.e., either an explicit select gesture or a TimeClick gesture) performed by the user toward the timer icon 38F.
In addition to the TimeClick mode, computer 26 may include one or more additional Select modes that enable user 22 to select a given alphanumeric key 38 using explicit select gestures. In some configurations, computer 26 may include separate Select modes for each of the explicit select gestures recognized by the computer.
In the configuration shown in FIG. 4, computer 26 presents a mode icon 38E that enables user 22 to toggle between the TimeClick mode and a given Select mode. In operation, computer 26 can actuate the TimeClick functionality upon detecting an explicit select gesture (e.g., a Pull, Push or Grab gesture) in the sequence of 3D maps received in step 54. While 3D user interface 20 is in the TimeClick mode, computer 26 can convey visual feedback such as illuminating mode icon 38E in a different color, or have the mode key blink on and off.
In some embodiments, computer 26 can implement a predictive text algorithm (also known as a language model) to aid user 22 in entering text via on-screen keyboard 70. The predictive text algorithm can implement techniques known in the art that predict the next alphanumeric key 38 to be selected by user 22 based on previously selected keys. For example, if user 22 has already selected the alphanumeric keys “N”, “E” and “X”, the predictive text algorithm may identify “T” as the next alphanumeric key to be selected.
Examples for integrating the predictive text algorithm for use with virtual keyboard 70 include:

    
    
        Increasing the active area for a given alphanumeric key 38 of a character identified by the predictive text algorithm. Using the example described supra, FIG. 4 shows the alphanumeric key “T” larger than the other alphanumeric keys. Increasing the active area can ease alphanumeric key selection in both the select mode and the TimeClick mode.
        Adjusting the position of interaction surface 46 for one or more characters identified (e.g., the letter “T” in the example described supra) by the predictive text algorithm. For example, if user 22 is performing a Push gesture, computer 26 can reposition interaction surface 46 closer to the user for the alphanumeric key “T”. Likewise, if user 22 is performing a Pull gesture, computer 26 can reposition interaction surface 46 closer to display 28 for the alphanumeric key “T”. Moving the interaction surface for specific alphanumeric keys 38 corresponding to characters identified by the predictive text algorithm can help the user enter text faster via the on-screen keyboard.
        Shortening the hold-time parameter for the alphanumeric keys corresponding to characters identified by the predictive text algorithm. In the example described supra, if the regular hold-time parameter is one second, the hold-time parameter for the alphanumeric key “T” can be shortened to 0.5 seconds, thereby enabling a proficient user to rapidly select the alphanumeric key “T”.
    
    


While interacting with traditional user interfaces such as keyboards, maintaining pressure on a particular alphanumeric key typically results in the particular key being repeated (e.g., pressing the “C” key results in “CCCCCCCC . . . ” being presented on the display). Due to the nature of interacting with the 3D user interface, user 22 may keep hand 30 steady after selecting one of alphanumeric keys 38. To reduce input errors, embodiments of the present invention may limit the repeating described supra to a subset of the alphanumeric keys, such as spacebar 38B, Backspace key 38D and arrow keys (not shown). Additionally or alternatively, keyboard 70 may comprise a clear key 38G, and computer 26 can be configured to clear any text in text box 74 when the clear key is selected.
FIG. 5 is a state diagram 80 that schematically illustrates the states and the transitions of computer 26 executing 3D user interface 20, in accordance with an embodiment of the present invention. Prior to user 22 selecting any interactive items 38 on display 28 using an explicit select gesture, computer 26 is in a TimeClick disengaged state 82. Upon user 22 performing an explicit select gesture in order to select given interactive item 38, computer 26 transitions to a TimeClick engaged state 84 via a touch transition 86.
While in state 84, user 22 can select interactive items 38 via TimeClick or via an explicit select gesture (i.e., using parameters for both the TimeClick and the select modes described supra). If, while in state 84, computer 26 repositions cursor 72 (or highlights a different interactive item 38) in response to a Find gesture performed by user 22, then the computer transitions to a timer active state 88 via a reposition cursor transition 90.
Alternatively, while in state 84, if computer 26 detects that user 22 has moved hand 30 to either a specific region within field of view 42 or outside field of view 42 (i.e., the computer cannot detect the hand), then the computer transitions back to state 82 via a release transition 92. For example, computer 26 can transition from the TimeClick engaged state to the TimeClick disengaged state via the release transition upon repositioning cursor 72 outside on-screen keyboard 70 in response to a Find gesture performed by the user.
Upon transitioning to timer active state 88, computer 26 may start a timer (typically a software module executing on the computer) upon presenting cursor 72 on a given interactive item (or highlighting the given interactive item) in response to a Find gesture performed by user 22. The timer keeps incrementing as long as computer 26 presents cursor 72 on the given interactive item (i.e., since user 22 is keeping hand 30 relatively steady). Computer 26 can select the given alphanumeric key upon the timer incrementing to a preset hold-time period (e.g., three seconds).
Alternatively, while in timer active state 88, computer 26 can select a given interactive item 38 in response to detecting user 22 performing an explicit select gesture while the computer presents cursor 72 on the given interactive item (or highlights the given interactive item if the cursor is not presented). As discussed supra, while in TimeClick mode (i.e., states 84 and 88), computer 26 may reposition reference interaction surface 46, thereby reducing the distance that user 22 needs to move hand 30 (and reducing or eliminating the wait time associated with TimeClick) in order to select the given interactive item via an explicit select gesture.
Upon selecting a given interactive item 38, computer 26 transitions back to state 84 via a select item transition 94. Alternatively, if computer 26 detects that user 22 has moved hand 30 to either a specific region within field of view 42 (e.g., so that the computer presents cursor 72 outside on-screen keyboard 70) or outside field of view 42 (i.e., the computer cannot detect the hand), then the computer transitions back to state 82 via a release transition 96. Further alternatively, upon computer 26 positioning cursor 72 on a different interactive item 38 (or highlighting a different interactive item 38) in response to user 22 performing a Find gesture, then computer 26 transitions to state 88 (i.e., from state 88) via a reposition cursor transition 98, and thereby restarts the timer.
Flashlight Cursor
FIGS. 6A and 6B are schematic pictorial illustrations of computer 26 presenting a flashlight cursor 100, in accordance with an embodiment of the present invention. In the description of FIGS. 6A and 6B herein, some of interactive items 38 may be differentiated by appending a letter to the identifying numeral, so that the interactive items presented on display 28 in FIG. 6A and 6B comprise interactive items 38H-38M.
The inventors selected a flashlight metaphor for cursor 100 since positioning the flashlight cursor is similar to aiming a flashlight. Typically, when an individual wants to illuminate a given physical region (e.g., an area on a wall) with a flashlight, the individual first turns on the flashlight, repositions the flashlight so that the given region is illuminated, and then holds the flashlight steady in order to keep the given region illuminated.
In embodiments of the present invention, user 22 can select a given interactive item 38 in a similar manner, by first pointing hand 30 toward display 28 in order to activate flashlight cursor 100, and then moving the hand in a transverse motion (i.e., along X-Y plane 40) in order to reposition the flashlight cursor over a given interactive item 38.
In the configuration shown in FIG. 6A, computer 26 presents items 38H-38M on display 28. In operation, if computer detects user 22 pointing hand 30 toward display 28, the computer determines the position (location and orientation) of the hand, and responsively presents flashlight cursor 100 at a corresponding location on display 28. In the example shown in FIG. 6A, computer 26 initially presents flashlight cursor 100 as a small shaded circle. Upon detecting, in the maps, user 22 moving hand 30 along X-Y plane 40, computer 26 repositions cursor 100 accordingly.
After positioning cursor 110 over a given interactive item 38, computer 26 can select the given interactive item upon detecting user 22 performing a TimeClick gesture while the flashlight cursor is positioned over the given interactive item. To select a given interactive item 38 using TimeClick, user 22 keeps hand 30 relatively still for a specific period of time (i.e., the hold-time described supra) while computer 26 positions cursor 110 over the given interactive item.
FIG. 6B is a schematic pictorial illustrations of user 22 selecting item 68 using TimeClick, in accordance with an embodiment of the present invention. In the example shown in FIG. 6B, as computer 26 presents flashlight cursor over interactive item 38K for the hold-time, the computer can gradually remove the shading from cursor 100 (i.e., terminating the animation effect), thereby bringing the interactive item 38K into focus.
While repositioning cursor 100, computer 26 can animate cursor 100 with a visual effect such as changing the color and/or shading presented within the cursor. Upon detecting, in the maps, user performing a TimeClick gesture, computer 26 can gradually change the appearance of cursor 100 by decreasing the visual effect during the hold-time period. In other words, computer 26 can select interactive item 38K as the interactive item “comes into focus” behind flashlight cursor 100.
FIG. 7 is a state diagram 110 that schematically illustrates the states and the transitions of computer 26 implementing flashlight cursor 100, in accordance with an embodiment of the present invention. Prior to user 22 performing a pointing gesture toward display 28, computer 26 is in a flashlight cursor off state 112.
Upon detecting, in the sequence of 3D maps, user 22 pointing hand 30 toward display 28, computer 26 transitions to flashlight cursor animated state 114 via a transition 116. While in state 114, computer 26 has not yet selected any of the interactive items presented on display 28, and the computer can present flashlight cursor 100 with a visual effect (e.g., animation), as shown in FIG. 6A. For example (i.e., while in state 114), computer 26 may detect, in the 3D maps, a transverse motion of hand 30 (i.e., along X-Y plane 40), and reposition flashlight cursor 100 on display 28 in response to the transverse motion.
While in state 114, if computer 26 detects (e.g., in the maps) that user 22 stops moving hand 30 for the hold-time, the computer can illuminate (i.e., “turns on”) flashlight cursor 100 upon transitioning to a flashlight cursor on state 118 via a transition 122. Upon transitioning to state 118 via transition 122, computer 26 can select a given interactive item 38 positioned “behind” the flashlight cursor. In the example shown in FIG. 6B, computer 26 selects interactive item 38K in response to detecting, in the maps, user 22 pointing hand 30 toward interactive item 38K and subsequently keeping hand 30 steady for the hold-time period. However, if computer 26 detects, user 22 no longer pointing hand 30 toward display 28 (e.g., by dropping the hand) while the computer is in state 114, then the computer transitions back to state 112 via a transition 120.
Returning to state 118, if computer 26 selects a given interactive item 38, and detects, user 22 still pointing hand 30 toward display 28, then the computer transitions back to state 114 via a transition 124. Alternatively (i.e., while in state 118), if computer 26 detects, user 22 ending the pointing gesture, then the computer transitions back to state 112 via a transition 126.
It will be appreciated that the embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features, including the transformations and the manipulations, described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.

## Claims

1. A method, comprising:
presenting, by a computer, multiple interactive items on a display coupled to the computer;
receiving, from a depth sensor, a sequence of three-dimensional (3D) maps containing at least a hand of a user of the computer at a variable distance from the depth sensor;
detecting, in the maps, an explicit select gesture performed by the user toward one of the interactive items;
selecting the one of the interactive items responsively to the explicit select gesture;
actuating, subsequent to selecting the one of the interactive items, a TimeClick functionality for subsequent interactive item selections to be made by the user; and
detecting, after actuating the TimeClick functionality, a TimeClick gesture directed at one of the subsequent interactive items, wherein the TimeClick gesture comprises the user keeping the hand relatively steady for a specific period of time, and wherein the specific time period is adjusted in response to the distance between the user and the depth sensor.

2. The method according to claim 1, and comprising presenting a cursor on the display, the cursor having a visual effect, and decreasing the visual effect upon detecting the user keeping the hand relatively steady for the specific period of time.

3. The method according to claim 1, and comprising adjusting the specific time period in response to a proficiency of the user.

4. The method according to claim 1, wherein the multiple interactive items comprise alphanumeric keys for an on-screen keyboard presented on the display, and comprising adjusting the specific time period in response to a predictive text algorithm.

5. The method according to claim 1, wherein one of the multiple interactive items comprises a TimeClick timer icon, and comprising adjusting the specific time period upon detecting, in the subsequent sequence of 3D maps a subsequent select gesture performed by the user toward the TimeClick timer icon.

6. The method according to claim 5, wherein the subsequent select gesture is selected from a list comprising the explicit select gesture and the TimeClick gesture.

7. The method according to claim 1, wherein one of the multiple interactive icons comprises a mode icon, and comprising actuating the TimeClick functionality upon detecting, in the sequence of 3D maps, the explicit select gesture toward the mode icon.

8. The method according to claim 1, wherein the explicit select gesture is selected from a list comprising a Push gesture, a Pull gesture, and a Grab gesture.

9. The method according to claim 1, and comprising prior to detecting the select gesture, defining coordinates for an interactive surface positioned in space in proximity to the user, and wherein completing the explicit select gesture comprises the hand crossing the interactive surface.

10. The method according to claim 9, wherein actuating the TimeClick functionality comprises redefining the coordinates of the interactive surface.

11. An apparatus, comprising:
a depth sensor; and
a computer executing a non-tactile three dimensional (3D) user interface and configured to present, multiple interactive items on a display coupled to the computer, to receive, from the depth sensor, a sequence of three-dimensional (3D) maps containing at least a hand of a user of the computer at a variable distance from the depth sensor, to detect, in the maps, an explicit select gesture performed by the user toward one of the interactive items, to select the one of the interactive items responsively to the explicit select gesture, and to actuate, subsequent to selecting the one of the interactive items, a TimeClick functionality for subsequent interactive item selections to be made by the user,
wherein the computer is configured to detect, after actuating the TimeClick functionality, a TimeClick gesture directed at one of the subsequent interactive items, wherein the TimeClick gesture comprises the user keeping the hand relatively steady for a specific period of time, and wherein the specific time period is adjusted in response to the distance between the user and the depth sensor.

12. The apparatus according to claim 11, wherein the computer is configured to present a cursor on the display, the cursor having a visual effect, and to decrease the visual effect upon detecting the user keeping the hand relatively steady for the specific period of time.

13. The apparatus according to claim 11, wherein the computer is configured to adjust the specific time period in response to a proficiency of the user.

14. The apparatus according to claim 11, wherein the multiple interactive items comprise alphanumeric keys for an on-screen keyboard presented on the display, and wherein the computer is configured to adjust the specific time period in response to a language model.

15. The apparatus according to claim 11, wherein one of the multiple interactive items comprises a TimeClick timer icon, and wherein the computer is configured to adjust the specific time period upon detecting, in the subsequent sequence of 3D maps a subsequent select gesture performed by the user toward the TimeClick timer icon.

16. The apparatus according to claim 15, wherein the computer is configured to select the subsequent select gesture from a list comprising the explicit select gesture and the TimeClick gesture.

17. The apparatus according to claim 11, wherein one of the multiple interactive icons comprises a mode icon, and wherein the computer is configured to actuate the TimeClick functionality upon detecting, in the sequence of 3D maps, the explicit select gesture toward the mode icon.

18. The apparatus according to claim 11, wherein the computer is configured to select the explicit select gesture from a list comprising a Push gesture, a Pull gesture, and a Grab gesture.

19. The apparatus according to claim 11, wherein the computer is configured to the define, prior to detecting the select gesture, coordinates for an interactive surface positioned in space in proximity to the user, and wherein completing the explicit select gesture comprises the hand crossing the interactive surface.

20. The apparatus according to claim 19, wherein the computer is configured to actuate the TimeClick functionality by redefining the coordinates of the interactive surface.

21. A computer software product comprising a non-transitory computer-readable medium, in which program instructions are stored, which instructions, when read by a computer executing a non-tactile user interface, cause the computer to present multiple interactive items on a display coupled to the computer, to receive, from a depth sensor, a sequence of three-dimensional (3D) maps containing at least a hand of a user of the computer at a variable distance from the depth sensor, to detect, in the maps, an explicit select gesture performed by the user toward one of the interactive items, to select the one of the interactive items responsively to the explicit select gesture, and to actuate, subsequent to selecting the one of the interactive items, a TimeClick functionality for subsequent interactive item selections to be made by the user,
wherein the computer is configured to detect, after actuating the TimeClick functionality, a TimeClick gesture directed at one of the subsequent interactive items, wherein the TimeClick gesture comprises the user keeping the hand relatively steady for a specific period of time, and wherein the specific time period is adjusted in response to the distance between the user and the depth sensor.