Small memory footprint light transport matrix capture

A method of generating light transport coefficients relating a digital projector to a digital camera, said digital projector having an array of projection pixels and said digital camera having an array of sensor pixel, said method comprising at least one processing unit to execute the following steps:

• (a) defining a first test image;
• (b) defining a second test image, each pixel within said first test image having a one-to-one corresponding with a pixel within said second test image;
• (c) defining a first set of first test patterns, each first test pattern within said first set defining a first group of selected projection pixels to be simultaneously activated and defining a first group of not-selected projector pixels to be simultaneously not-activated;
• (d) defining a second set of second test patterns, each second test pattern within said second set defining a second group of selected projection pixels to be simultaneously activated and defining a second group of not-selected projector pixels to be simultaneously not-activated;
• (e) using said digital projector to project, each in turn, said first test patterns;
• (f) using said digital camera to capture, each in turn, each projected first test pattern;
• (g) checking each captured first test pattern by comparing the captured light intensity value of each pixel of said captured first test pattern with a corresponding pixel in said first test image, and if the captured light intensity value being compared is greater than that of the corresponding pixel in said first test image, then over-writing the corresponding pixel with the captured light intensity value, otherwise leaving said corresponding pixel unchanged;
• (k) comparing, pixel-by-pixel, the intensity value of each pixel within said first test image with the intensity value in its corresponding pixel within said second test image, storing the lower intensity value.