Diffusion networks for on-chip image contrast normalization

A new method for normalizing and quantizing images is presented. The method is based on calculating a local reference frame for the image gray levels. The levels of the reference frame are calculated using biased diffusions that are linked to the original image. The method is conceived to be integrated with sensing elements on the image plane of a camera. Its mathematical properties are analyzed and its performance is experimentally demonstrated. A circuital implementation has been designed, constructed and tested; it consists of a 20 nodes 1-D non-linear resistive grid. Experimental results are shown