Abstract:
A method for determining the location of a touch input in an application window on an interactive surface of a display device is described. The application window comprises a canvas configured to display at least a portion of a user interface. The method comprises the following steps. A first location of the touch input associated with a first coordinate space is determined. The first coordinate space is associated with the interactive surface. The touch input is used to emulate a mouse event. A second location of the touch input associated with a second coordinate space is determined in response to the emulated mouse event. The second coordinate space is associated with the user interface. At least one offset parameter is calculated, correlating the first coordinate space with the second coordinate space. While the first coordinate space does not change with respect the second coordinate space, the at least one offset parameter is used to determine the location of subsequent touch inputs based on corresponding locations associated with the first coordinate space. A computer readable medium and an interactive input system for implementing the method are also described.

Description:
[0001]    The subject application relates generally to an interactive input system, and in particular, to a system and method for injecting pointer input into an application window. This application claims priority from U.S. Provisional Application No. 61/720,331, titled “An Interactive Input System and Method Therefor”, filed Oct. 30, 2012. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Interactive input systems that allow users to inject input such as for example digital ink, mouse events etc. into an application program using an active pointer (e.g. a pointer that emits light, sound or other signal), a passive pointer (e.g., a finger, cylinder or other object) or other suitable input device such as for example, a mouse or trackball, are well known. These interactive input systems include but are not limited to: touch systems comprising touch panels employing analog resistive or machine vision technology to register pointer input such as those disclosed in U.S. Pat. Nos. 5,448,263; 6,141,000; 6,337,681; 6,747,636; 6,803,906; 7,232,986; 7,236,162; and 7,274,356 and in U.S. Patent Application Publication No. 2004/0179001, all assigned to SMART Technologies ULC of Calgary, Alberta, Canada, assignee of the subject application, the entire disclosure of which are incorporated herein by reference; touch systems comprising touch panels employing electromagnetic, capacitive, acoustic or other technologies to register pointer input; tablet and laptop personal computers (PCs); personal digital assistants (PDAs) and other handheld devices; and other similar devices. 
         [0003]    Although efforts have been made to make software applications more user-friendly, it is still desirable to improve user experience of software applications used in interactive input systems. It is therefore an object to provide a novel method for for manipulating a graphical user interface in an interactive input system. 
       SUMMARY OF THE INVENTION 
       [0004]    In accordance with one aspect of the present invention there is provided a method for determining the location of a touch input in an application window on an interactive surface of a display device, the application window comprising a canvas configured to display at least a portion of a user interface; the method comprising: determining a first location of the touch input associated with a first coordinate space, the first coordinate space being associated with the interactive surface; using the touch input to emulate a mouse event; determining a second location of the touch input associated with a second coordinate space in response to the emulated mouse event; the second coordinate space being associated with the user interface; calculating at least one offset parameter correlating the first coordinate space with the second coordinate space; and while the first coordinate space does not change with respect the second coordinate space, using the at least one offset parameter to determine the location of subsequent touch inputs based on corresponding locations associated with the first coordinate space. 
         [0005]    In accordance with further aspects of the invention, there are provided a computer readable medium and an interactive input system for implementing the method described above. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    An embodiment of the invention will now be described by way of example only with reference to the following drawings in which: 
           [0007]      FIG. 1  is a perspective view of an interactive input system; 
           [0008]      FIG. 2  illustrates exemplary software architecture used by the interactive input system of  FIG. 1 ; 
           [0009]      FIG. 3  illustrates an exemplary application window of a web browser; 
           [0010]      FIG. 4  illustrates a flowchart showing steps for injecting touch input events into a webpage displayed in the web browser; 
           [0011]      FIG. 5  illustrates calibration parameters of the application window of  FIG. 3  for performing the touch calibration; 
           [0012]      FIG. 6  is an exemplary application window with digital ink applied over a text input area; 
           [0013]      FIGS. 7  is the application window of  FIG. 6  in which the digital ink has been converted to text and added to the text input area. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]    For convenience, like numerals in the description refer to like structures in the drawings. Referring to  FIG. 1 , an interactive input system is shown and is generally identified by reference numeral  100 . Interactive input system  100  allows one or more users to inject input such as digital ink, mouse events, commands, and the like into an executing application program. In this embodiment, interactive input system  100  comprises an interactive display device  102  in the form of an interactive whiteboard (IWB) mounted on a vertical support surface such as a wall surface, for example, or the like. IWB  102  comprises a generally planar, rectangular interactive surface  104  that is surrounded about its periphery by a bezel  106 . A projector  108  is mounted on a support surface above the IWB  102  and projects an image, such as a computer desktop for example, onto the interactive surface  104 . In this embodiment, the projector  108  is an ultra-short-throw projector such as that sold by SMART Technologies ULC of Calgary, Alberta, Canada, assignee of the subject application, under the name “SMART UX60”, 
         [0015]    The IWB  102  employs machine vision to detect one or more pointers brought into a region of interest in proximity with the interactive surface  104 . The IWB  102  communicates with a general purpose computing device  110 , executing one or more application programs, via a suitable wired or wireless communication link  112 . In this embodiment, the communication link  112  is a universal serial bus (USB) cable. The general purpose computing device  110  processes output from the IWB  102  and adjusts image data that is output to the projector  108 , if required, so that the image presented on the interactive surface  104  reflects pointer activity. In this manner, the IWB  102 , general purpose computing device  110  and projector  108  allow pointer activity proximate to the interactive surface  104  to be recorded as writing or drawing or used to control execution of one or more application programs executed by the general purpose computing device  110 . 
         [0016]    The bezel  106  is mechanically fastened to the interactive surface  104  and comprises four bezel segments that extend along the edges of the interactive surface  104 . In this embodiment, the inwardly facing surface of each bezel segment comprises a single, longitudinally extending strip or band of retro-reflective material. To take best advantage of the properties of the retro-reflective material, the bezel segments are oriented so that their inwardly facing surfaces lie in a plane generally normal to the plane of the interactive surface  104 . 
         [0017]    A tool tray  114  is affixed to the IWB  102  adjacent the bottom bezel segment using suitable fasteners such as for example, screws, clips, adhesive etc. As can be seen, the tool tray  114  comprises a housing having an upper surface configured to define a plurality of receptacles or slots. The receptacles are sized to receive one or more pen tools  116  as well as an eraser tool  118  that can be used to interact with the interactive surface  104 . Control buttons (not shown) are also provided on the upper surface of the tool tray housing to enable a user to control operation of the interactive input system  100 . Further specifies of the tool tray  114  are described in U.S. Patent Application Publication No. 2011/0169736 to Bolt et al., filed on Feb. 19, 2010, and entitled “INTERACTIVE INPUT SYSTEM AND TOOL TRAY THEREFOR”, the content of which is incorporated herein by reference in its entirety. 
         [0018]    Imaging assemblies (not shown) are accommodated by the bezel  106 , with each imaging assembly being positioned adjacent a different corner of the bezel. Each of the imaging assemblies comprises an image sensor and associated lens assembly that provides the image sensor with a field of view sufficiently large as to encompass the entire interactive surface  104 . A digital signal processor (DSP) or other suitable processing device sends clock signals to the image sensor causing the image sensor to capture image frames at the desired frame rate. During image frame capture, the DSP also causes an infrared (IR) light source to illuminate and flood the region of interest over the interactive surface  104  with IR illumination. Thus, when no pointer exists within the field of view of the image sensor, the image sensor sees the illumination reflected by the retro-reflective bands on the bezel segments and captures image frames comprising a continuous bright band. When a pointer exists within the field of view of the image sensor, the pointer occludes reflected IR illumination and appears as a dark region interrupting the bright band in captured image frames. 
         [0019]    The imaging assemblies are oriented so that their fields of view overlap and look generally across the entire interactive surface  104 . In this manner, any pointer such as for example a user&#39;s finger, a cylinder or other suitable object, a pen tool  116  or an eraser tool  118  lifted from a receptacle of the tool tray  114 , that is brought into proximity of the interactive surface  104  appears in the fields of view of the imaging assemblies and thus, is captured in image frames acquired by multiple imaging assemblies. When the imaging assemblies acquire image frames in which a pointer exists, the imaging assemblies convey pointer data to the general purpose computing device  110 . 
         [0020]    The general purpose computing device  110  in this embodiment is a personal computer or other suitable processing device comprising, for example, a processing unit, system memory (volatile and/or non-volatile memory), other non-removable or removable memory (e.g., a hard disk drive, RAM, ROM, EEPROM, CD-ROM, DVD, flash memory, etc.) and a system bus coupling the various computer components to the processing unit. The general purpose computing device  110  may also comprise networking capabilities using Ethernet, WiFi, and/or other suitable network format, to enable connection to shared or remote drives, one or more networked computers, or other networked devices. A mouse  120  and a keyboard  122  are coupled to the general purpose computing device  110 . 
         [0021]    The general purpose computing device  110  processes pointer data received from the imaging assemblies to resolve pointer ambiguity by combining the pointer data detected by the imaging assemblies, and to compute the locations of pointers proximate the interactive surface  104  (sometimes referred as “pointer contacts”) using well-known triangulation. The computed pointer locations are then recorded as writing or drawing or used as an input command to control execution of an application program as described above. 
         [0022]    In addition to computing the locations of pointers proximate to the interactive surface  104 , the general purpose computing device  110  also determines the pointer types (e.g., pen tool, finger or palm) by using pointer type data received from the IWB  102 . Here, the pointer type data is generated for each pointer contact by at least one of the imaging assembly DSPs by differentiating a curve of growth derived from a horizontal intensity profile of pixels corresponding to each pointer tip in captured image frames. Specifics of methods used to determine pointer type are disclosed in U.S. Pat. No. 7,532,206 to Morrison, et al., and assigned to SMART Technologies ULC, the disclosure of which is incorporated herein by reference in its entirety. 
         [0023]    A software program running in the computing device  110  presents, via the projector  108 , an image representing a graphic user interface on the interactive surface  104 . The software program processes touch input generated from the interactive surface  104 , and adjusts the image on the interactive surface to allow users to manipulate the graphic user interface. Referring to  FIG. 2  an exemplary software architecture used by the interactive input system  100  is shown and is generally identified by reference numeral  140 . The software architecture  140  comprises an input interface layer  142  and an application layer  144  comprising one or more application programs. The input interface layer  142  is configured to receive input from various input sources generated from the input devices of the interactive input system  100 . The input devices include the IWB  102 , the mouse  120 , the keyboard  122 , and other input devices, depending on the implementation. The input interface layer  142  processes received input and generates input events, such as touch events  146 , mouse events  148 , keyboard events  150  and/or other input events  152 . The generated input events are then transmitted to the application layer  144  for processing. 
         [0024]    As one or more pointers contact the interactive surface  104  of the IWB  102 , associated touch events are generated. The touch events are generated from the time the one or more pointers are brought into contact with the interactive surface  104  (referred to as a contact down event) until the time the one or more pointers are lifted from the interactive surface  104  (referred to as a contact up event). As will be appreciated, a contact down event is similar to a mouse down event in a typical graphical user interface utilizing mouse input, wherein a user presses the left mouse button. Similarly, a contact up event is similar to a mouse up event in a typical graphical user interface utilizing mouse input, wherein a user releases the pressed mouse button. A contact move event is generated when a pointer is contacting and moving on the interactive surface  104 , and is similar to a mouse drag event in a typical graphical user interface utilizing mouse input, wherein a user moves the mouse while pressing and holding the left mouse button. 
         [0025]    In this embodiment, one of the applications in the application layer  144  is a web browser such as Google Chrome, Mozilla Firefox, Internet Explorer or the like. As is known, a web browser accepts a Universal Resource Identifier (URI) as input. The URI is an identifier, such as an address of a website for example, that identifies the location of a webpage. The web browser accesses the webpage identified by the URI, retrieves data, and displays the retrieved webpage in a browser window. 
         [0026]    Referring to  FIG. 3  an exemplary application window of a web browser is shown and generally identified by numeral  200 . The application window  200  comprises a canvas  202  and a plurality of other window components such as a title bar  204 , a toolbar  206 , a menu bar  208 , one or more webpage tabs  210  and a sidebar  212 , for example. The web browser loads a webpage  214  to be displayed on the canvas  202 . If the size of the webpage  214  is larger than that of the canvas  202 , only a portion of the webpage  214  is displayed on the canvas  202  at a given time. A vertical scrollbar  216  and/or a horizontal scrollbar  218  are provided to facilitate panning the webpage  214  so that different portions can be displayed on the canvas  202 , as desired. 
         [0027]    The web browser also provides an application program interface (API) to allow one or more extension modules, referred to as addons or plug-ins, to be installed. The addons/plug-ins provides the ability to expand the functionality of the web browser. In this embodiment, the web browser includes a touch input addon to provide touch functionality to the web browser. The touch input addon is configured to inject touch script code, such as JavaScript code for example, into the webpage  114  as it is loaded by the web browser. The touch script code is configured to provide functionality to the web browser so that touch input can be injected into the webpage displayed in the application window  200 , as will be described below. 
         [0028]    Referring to  FIG. 4  a flowchart showing steps for injecting touch input events into the webpage  214  displayed in the application window  200  is shown and generally illustrated by numeral  300 . At step  302 , the web browser is launched. At step  303 , the webpage  214  is loaded. As part of loading the webpage  214 , the touch input addon injects the touch script code into webpage. The touch script code is configured to direct the web browser to communicate with the input interface layer  142  and receive notification of touch events while the webpage  214  is loaded. At step  304 , a notification of a touch event is received. A touch event is considered to be a touch input received on the canvas  202 . Any touch input received outside of the canvas  202  is treated as is standard in the art, for example as a mouse click. 
         [0029]    At step  306 , in response to the touch event, the touch script code determines whether or not to perform touch calibration. In this embodiment, touch calibration is performed when a position of the webpage  214  on the canvas  202  changes. For example, touch calibration is performed when the webpage  214  is loaded into the web browser, when the application window  200  is moved to another location, when the application window  200  is resized, when components of the application window  200  (for example the sidebar  214 , toolbar  206 , menu bar  208  and the like) are changed so that the size and/or position of the canvas  202  is changed, or when the webpage  214  displayed on the canvas  202  is panned to a different portion. 
         [0030]    If it is determined that touch calibration is required, then at step  308  the touch script code converts the received touch event into a mouse event and injects the mouse event into the application window  200 . As is known in the art, in response to a mouse event, the web browser determines a location of the mouse within a reference frame of the webpage  214 . At step  310 , touch calibration is performed using calibration parameters provided by the web browser and the mouse location determined in step  308  to determine offset parameters. Details of the touch calibration  310  will be described with reference to  FIG. 5 . Then, at step  312 , the touch event is injected into the application window  200 . This is achieved by applying the offset parameters to the identified pointer location of the touch event to determine a location of the touch event within the reference frame of the webpage  214 . 
         [0031]    If it is determined that touch calibration is not required, the touch input addon continues at step  312  and the touch event is injected into the browser application window  200 . 
         [0032]    Referring to  FIG. 5 , calibration parameters of the application window  200  for performing the touch calibration are shown and generally illustrated by numeral  400 . For ease of illustration, some window components, such as the title bar  204 , toolbar  206  and menu bar  208  of the application window  200  are not shown. As previously described, the application window  200  is displayed on the interactive surface  104 . The application window  200  displays the webpage  214 , or a portion of the webpage  214 , on the canvas  202 . 
         [0033]    A screen coordinate system (X-Y) is defined for the IWB. In this embodiment, the origin of the screen coordinate system is located at an upper-left corner of the interactive surface  104 . The X-axis of the screen coordinate system increases towards the right. The Y-axis of the screen coordinate system increases downwardly. It is assumed that the IWB  102  has been calibrated as is known in the art, so that any touch input on the interactive surface  104  will be properly mapped to a location of the display image output from the computing device  110  in the screen coordinate system. 
         [0034]    A webpage coordinate system (X′-Y′) is defined for the webpage  214 . In this embodiment, the origin of the webpage coordinate system is located at an upper-left corner of the webpage  214 . The X-axis of the webpage coordinate system increases towards the right. The Y-axis of the webpage coordinate system increases downwardly. As will be appreciated, the webpage coordinate system may move with respect to the screen coordinate system when the webpage  214  is loaded, changed or panned, which is why the touch calibration is performed. 
         [0035]    The touch script code retrieves a variety of information about the application window  200  from the web browser, including an application window location and a webpage offset. The application window location refers to a location of the application window on the interactive surface  104  and is represented by an upper-left corner  342  of the application window. Accordingly, the application window location  342  in the screen coordinate system is at location (X 1 , Y 1 ). The webpage offset refers to an offset between the origin of the webpage coordinate system and a point of the webpage displayed in an upper left corner  344  of the canvas  202 . Accordingly, the webpage offset in the webpage coordinate system is at location (X′ 1 , Y′ 1 ). 
         [0036]    When a touch event is received at step  304 , the input interface layer  142  reports the location (X 2 , Y 2 ) of the touch event in the screen coordinate system. If calibration is to be performed then at step  308  the touch event is converted to a mouse event and injected into the application window. In response, the web browser reports the location (X′ 2 , Y′ 2 ) of the mouse event in the webpage coordinate system. At step  310  the touch calibration is performed by calculating the offset parameters. Specifically, in this embodiment a horizontal offset xOffset and a vertical offset yOffset are calculated as follows: 
         [0000]      ( x Offset,  y Offset)=(mouse event location in screen coordinate system)−(window position in screen coordinate system)−(mouse event location in webpage coordinate system)+(webpage offset);
 
         [0000]    or, using the locations described above: 
         [0000]        x Offset= X 2− X 1− X′ 2+ X′ 1,
 
         [0000]        y Offset= Y 2− Y 1− Y′ 2+ Y′ 1.
 
         [0037]    When injecting touch event into application window at step  312 , the calculated offset parameters (xOffset, yOffset) are used for determining the touch event location in the webpage coordinate system as: 
         [0000]      (touch event location in webpage coordinate system)=(mouse event in screen coordinate system)−(window position in screen coordinate system)−(xOffset, yOffset)+(webpage offset).
 
         [0038]    Thus it will be appreciated that the mouse event is used to facilitate determining the offset parameters. Once the offset parameters have been determined, they can be applied to the touch event location without necessitating a mouse event to in order to determine the touch event location in the webpage coordinate system. This allows web browsers, as well as other applications, that are not specifically developed for use with interactive display devices  102  to be used seamlessly therewith. 
         [0039]    Further, in addition to location, the touch event injected into the application window  200  may comprise a plurality of other parameters, such as a pointer type (pen tool or a finger for example), the colour of the pen tool, and the like. The parameters could not be conveyed by emulating a mouse event. The touch script code responds to received touch events based, at least in part, on the parameters of the touch events. For example, if the touch script code determines from the pointer type parameter of the touch event that a finger is touching the application window, the touch script code can process the touch event as for injecting user commands, such as panning the webpage, selecting text or images, clicking a link, and the like. As another example, if the touch script code determines from the pointer type parameter of the touch event that a pen tool is touching the application window, the touch script code can process the touch event as injecting digital ink to allow a user to write digital ink on the webpage  214  or into a text input area as text. 
         [0040]    Referring to  FIGS. 6 and 7 , an exemplary application window  200  is shown. The application window  200  includes a webpage  214  having a text input area  380 . A user (not shown) uses a pen tool  382  to hand-write digital ink  384  in the canvas  202  of the application window  200 . The web browser, with the assistance of the touch script code, calibrates the touch input as described above when the first touch event is received. The touch script code then determines from the calibrated touch events that a pen tool is used for injecting the digital ink  384 . The touch script code also calculates the position of the digital ink  384  in the webpage coordinate system as described above. Based on the calculated position, it is determined that the injected digital ink overlaps the text input area  380 . The digital ink is completed when the user lifts the pen tool  382  from the interactive surface  104 . After a predetermined time threshold has passed, the touch script code converts the injected digital ink  384  into text, injects the converted text into the text input area  380 , as shown in  FIG. 7 , and removes the digital ink from the interactive surface  104 . 
         [0041]    In this embodiment, the digital ink  384  is converted from hand-writing to text using a suitable one of a plurality of known text recognition mechanisms. The code and/or libraries associated with the text recognition may be local to the computing device  110  or located on one of the networked computers. Also in this embodiment, if the digital ink injected by the user does not overlap any text input area, the touch script code automatically fades out the injected digital ink after the predetermined time threshold. 
         [0042]    Although in the embodiments described above, a web browser with a touch input addon/plug-in is used, in an alternative embodiment, the touch input functionalities may be directly implemented by the web browser. In yet an alternative embodiment, bookmarklets may be used to implement the touch script code. A bookmarklet is a bookmark that comprises script code. The bookmarklet can be added to the bookmark menu or bookmark toolbar manually by the user, or automatically by an installation application. However, the user has to select the bookmarklet, from a bookmark menu or toolbar for example, to execute the touch script code, thereby facilitating touch functionality. In yet an alternative embodiment, web developers can include the touch script code in their webpages so there is no need for anything different at the web browser. In some other embodiments, the software application may take other forms, such as for example, a desktop or a mobile application using web technologies. 
         [0043]    In the above description, specific reference is made to a web browser and webpages. The invention, however, can be used with other types of applications. Generally speaking, the touch script code can be applied to any suitable markup language document that is rendered by a corresponding application to display a user interface in an application window. 
         [0044]    In above description, the software program may comprise program modules including routines, object components, data structures, and the like, and may be embodied as computer readable program code stored on a non-transitory computer readable medium. The computer readable medium is any data storage device that can store data. Examples of computer readable media include for example read-only memory, random-access memory, CD-ROMs, magnetic tape, USB keys, flash drives and optical data storage devices. The computer readable program code may also be distributed over a network including coupled computer systems so that the computer readable program code is stored and executed in a distributed fashion. Yet further, additional software may be provided to perform some of the functionality of the touch script code, depending on the implementation. 
         [0045]    Although in embodiments described above, the IWB is described as comprising machine vision to register pointer input, those skilled in the art will appreciate that other interactive boards employing other machine vision configurations, analog resistive, electromagnetic, capacitive, acoustic or other technologies to register input may be employed. Further, machine vision different to that described above may also be used. 
         [0046]    For example, products and touch systems may be employed such as for example: LCD screens with camera based touch detection (for example SMART Board™ Interactive Display—model 8070i); projector based IWB employing analog resistive detection (for example SMART Board™ IWB Model 640); projector based IWB employing a surface acoustic wave (WAV); projector based IWB employing capacitive touch detection; projector based IWB employing camera based detection (for example SMART Board™ model SBX885ix); table (for example SMART Table™—such as that described in U.S. Patent Application Publication No. 2011/069019 assigned to SMART Technologies ULC of Calgary, the entire contents of which are incorporated herein by reference); slate computers (for example SMART Slate™ Wireless Slate Model WS200); podium-like products (for example SMART Podium™ Interactive Pen Display) adapted to detect passive touch (for example fingers, pointer, etc,—in addition to or instead of active pens); all of which are provided by SMART Technologies ULC of Calgary, Alberta, Canada. 
         [0047]    Other types of products that utilize touch interfaces such as for example tablets, smart-phones with capacitive touch surfaces, flat panels having touch screens, IWBs, a track pad, and the like may also be employed. 
         [0048]    Although embodiments have been described above with reference to the accompanying drawings, those of skill in the art will appreciate that variations and modifications may be made without departing from the scope thereof as defined by the appended claims.