Touchscreen%20 implementation%20for%20multi touch-new[1] (1)

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Interactive Multi-Touch Powerpoint prsentation

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  • Introductions
  • Touchscreen%20 implementation%20for%20multi touch-new[1] (1)

    1. 1. SURFACE COMPUTING & MULTI-TOUCH DISPLAY DEVICES
    2. 2. Introduction  Surface computing is the term for the use of a specialized computer GUI in which traditional GUI elements are replaced by intuitive, everyday objects. Instead of a keyboard and mouse, the user interacts directly with a touch- sensitive screen.
    3. 3.  Surface Computing Advertisement
    4. 4.  Description  The multi-touch device is a user interface device that will allow a user to interact with a computer through use of a multi-touch display. Thus, it is a substitute to the keyboard and mouse. In this user can directly interact with the system with their fingers and not only this but with multiple touches at the same instant.
    5. 5.   A basic touch-screen has three main components:  1. Touch sensor;  2. Controller;  3. Software driver.  The touch-screen is an input device, so it needs to be combined with a display and a PC or other device to make a complete touch input system. How Does a Touchscreen Work? 
    6. 6. Touchscreen Technologies  Resistive  Capacitive  Surface  Projected  Optical imaging  FTIR  DI  DSI
    7. 7. Resistive Touchscreen  Composed of multiple layers separated by thin spaces  Using indium tin oxide (ITO) layers  Different standards  4, 5, and 8 wire types  Each have advantages
    8. 8. Resistive Touchscreen  User Presses Down  Contact is Made  Uniform Voltage on First Screen for X  Same on Second screen for Y  Happens instantaneously
    9. 9. 4-Wire design  One screen for X  Another screen for Y  Both create voltage gradient.  Uses voltage divider
    10. 10. Advantages & Disadvantages  Works well with fingertip or stylus input  Generally most affordable touchscreen technology  Rugged/Durable  Has multi-touch input capabilities  Not as accurate  Multi-touch much more complex  Usually no discretion between stylus and hand  More pressure needed
    11. 11. Capacitive Touch Technology  Consists of:  Insulator (glass or Air)  Conductive coating (ITO)  Two types:  Surface  projected
    12. 12. Surface Capacitance  Only one side is coated  Electrodes at the edges  Distribute voltage
    13. 13.  Capacitor forms  Current flows  Determine location  Controller  Ratio of currents ,  XY coordinates A R ρ× =   1 αi R Surface Capacitance
    14. 14. Projected Capacitance  Two parallel ITO(Indium Tin Oxide ) layers  Two sheets of glass
    15. 15. Projected Capacitance  E Field is projected through glass  Finger couples with E field  Capacitance changes Capacitor at each point on the surface
    16. 16. Surface vs. Projected  Limited resolution  Single touch  Operation with direct contact  High resolution  Multi touch  Operation with indirect contact
    17. 17.  Multi-Touch Using Infrared
    18. 18. Frustrated Total Internal ReflectionFrustrated Total Internal Reflection A process by which light is trapped within a medium and can be interrupted by a third medium of higher reflective index to cause light to escape.
    19. 19. Diffused Illumination
    20. 20.  Diffused Surface Illumination
    21. 21. Alternative Single-Unit Design Eliminates rear projection Expensive Robustness
    22. 22.  Software Surface Capture via Detector Digitized View
    23. 23. Software Cont.  Interpret and Relay Information  Assign Objects or gestures with Unique ID# and location  Compare and Execute Digitized Object Application ProtocolRaw Data Feedback to User
    24. 24.   Universal Design Principles  Utility for all users  Simple and intuitive  Touchscreens depend on visual feedback in order to use Improving Accessibility?
    25. 25.   Cursor movements as command shortcuts  Takes place of keyboard shortcuts  Useful in applications where keyboard use is less prominent or undesirable Pointing Device Gestures Above: Some possible cursor movement patterns for use in gesture support.
    26. 26. Implementation: Step 1  Filter Input  Sampling rate  Smooth out input data, get rid of unnecessary “noise”  Simplify data analysis
    27. 27. Implementation: Step 2  Vectorize  Separate x- and y-component  Compute dominant component and ignore smaller one  Store in array
    28. 28. Implementation: Step 3  Matching  Match captured vector array to pre-defined gesture library  If no match, pop smallest vector from array and repeat matching process
    29. 29. Example Fig. 1 – User input Fig. 2 – Captured/filtered pointer data Fig. 3 – After vectorization Fig. 4 – Final matching result
    30. 30.   Allows for a quicker and more efficient UI  Universal Design  Enhances usability for visually-impaired as well as non-impaired  Easily added to existing touchscreen devices, no additional hardware required Goal
    31. 31.   A personal computerwith 20 GBfree hard disk space, 1GBRAMand PIV + processorcan be efficient enough.  The Windows Vista operating systemwas chosen because the CCV package is highly supported in Windows. Computer Subsystem
    32. 32.   Many different platforms can be used to develop multi-touch applications utilizing TUIO events. Such platforms include:  Adobe Flash  Java  C++  Python Application Development
    33. 33.   Personal Computing  Graphics  Audio Mixing  Video Playing  ComputerGaming  Slide Presentations ……and many more! APPLICATIONS

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