This design idea utilizes inexpensive webcams to add touch input and smart board features to ANY monitor.
The webcams are pointed at the screen from the left and right sides at a distance of about one foot. Each of the images is corrected for trapezoidal distortion due to the imaging angle in software.
Object recognition software detects the orientation of hands, finger locations and motion, calculating the activation touch point from the two parallax image planes provided by the two webcams.
The touch point is compared to the original image in the memory map determining the function to activate.
Estimated cost for adding the touch function is around $40, basically the cost of two webcams and plastic extension brackets.