Size/scale orientation determination of a pointer in a camera-based touch system

A method comprising:

• acquiring at least first and second images of a pointer proximate an input surface from different vantages;
• processing pixel data of each image to determine at least a pair of edges of said pointer;
• calculating an input area of said pointer using triagulation based on the determined pairs of edges, the input area representing the size of said pointer;
• and
• updating a computer generated image displayed on said input surface based at least in part on the pointer size.

A method comprising:

• acquiring at least first and second images looking generally across an input surface from different vantages;
• processing pixel data of each image to determine if a pointer exists in said image and if so, processing pixel data to determine at least a pair of edges of said pointer;
• calculating an input region of said pointer using triagulation based on the determined pairs of edges;
• and
• in response to the calculated input region, updating a computer generated image displayed on said touch surface.

A method comprising:

• acquiring at least first and second images of a pointer proximate an input surface from different vantages;
• processing pixel data of each image that is associated with different regions of said pointer along its length to determine at least a pair of edges of said pointer for each region;
• for each region of said pointer, triangulating an area of said pointer based on the determined pairs of edges for the region;
• and
• stacking the triangulated areas thereby to generate a volumetric representation of said pointer.