1. A touch system comprising: a substantially rectangular frame configured to surround a region of interest in front of a display surface; at least two digital cameras, each digital camera having a selectable pixel array and being mounted adjacent a different corner of said frame, each digital camera having a field of view that extends at least beyond a peripheral edge of said frame, said digital cameras being oriented to capture overlapping images of said region of interest; and at least one processor processing a subset of pixel data of images captured by the digital cameras to detect the existence of a pointer therein, said at least one processor further processing image data of each digital camera to compensate for an angle between a field of view of each digital camera and at least a portion of said periphery of said frame as a reference.