Active In SP
Joined: Feb 2011
28-02-2011, 03:13 PM
Nadeem Abdul Rub Nistar
TouchLight.ppt (Size: 4.82 MB / Downloads: 78)
Touchlight compute a touch image on a plane situated between a pair of cameras and the user.
Developed by microsoft.
A project and implimentationion display material project and implimentations an image onto a transparent sheet of acrylic plastic.
It permits a high resolution touch image.
Instead of a small list of discrete points, a full touch image is computed
A pair of commonly available web cameras are mounted behind the display surface such that each camera can see all four corners of the display.
The HoloScreen is a special refractive holographic film which scatters light from a rear project and implimentationor when the incident light is at a particular angle.
The material is transparent to all other light.
The project and implimentationor is mounted such that the project and implimentationed light strikes the display at an angle of about 35 degrees
An IR illuminant is placed behind the display to illuminate the surface evenly in IR light.
Restricts the project and implimentationed light to the visible spectrum, and the sensed light to the IR spectrum.
Finally, a microphone is rigidly attached to the display surface to enable the simple detection of “knocking” on the display.
Except for the microphone, there are no wires attached, making TouchLight more robust for public installation.
Compute an image of the objects touching the surface of the display, such as the user’s hand.
Due to the transparency of the display, each camera view shows the objects on the display and objects beyond the surface of the display, including the background and the rest of the user.
With two cameras, the system can determine if a given object is on the display surface or above it.
TouchLight image processing acts as a filter to remove objects not on the display surface.
Produces a touch image which shows objects that are on the display surface and is blank everywhere else.
The touch image is produced by directly combining the output of the two video cameras.
After rectification the same point in both left and right refer to the same point on the display surface
Strong IR illuminant is usedto identify hands and other IR reflective materials on the display surface.
It is possible to arrange two distinct bright objects above the display surface such that they are fused as a single object on the surface.
The image rectification and image comparison processes do not require the physical presence of the display.
It is possible to configure TouchLight to operate without the HoloScreen, in which case the “touch” interaction is performed on an invisible plane in front of the user.
In this case, it may be unnecessary to perform imaging in IR.
Touch Image Interpretation
Binarize the touch image, and compute connected components to find distinct objects on the surface.
Mouse control algorithms are used fordetection and tracking.
The position of this object determines the mouse position.
Region in the lower left corner of the display functions as a left mouse button: