Patent ID: 8774553

Claim:
A method of enhancing an image comprising the steps of: dividing a previous input image into multiple tiles; constructing a histogram for each tile; dividing the histogram of each tile into multiple portions, each portion representing a count of pixels spanning across successive pixel intensity value bands; constructing a cumulative distribution function (CDF) for each of the multiple portions; receiving a present image; determining an intensity value for a pixel in the present image; finding four adjacent tiles in the previous image that surround the pixel in the present image; selecting a CDF of each portion that includes the intensity value of the pixel in the present image; transforming the intensity value of the pixel in the present image based on selected CDFs of each portion constructed for the four adjacent tiles in the previous image to obtain four intensity levels; and using bilinear interpolation to calculate a single intensity value of the pixel in the present image based on the four intensity levels.