Patent ID: 7242500
Filing Date: 2007-07-10
Classification: G06T,H04N

Abstract:
1. A method for down-sampling a halftone color image having an original resolution value in dots-per-inch comprising acquiring, for each color channel, image-scan pixel data, and utilizing that per-color-channel image-scan data, successively examining different groups of four pixels to determine the respective pixel-color-values of those pixels, wherein each such examined group includes (a) a first pair of next-adjacent pixels that are column-arranged, (b) a second pair of next-adjacent pixels that are row-arranged, and (c) a pixel which is common to and shared by both such pairs, and performing a defined averaging algorithm relative to such determined pixel-color-values in each such group, including, for each such group of four pixels, utilizing the respective pixel-color-values thereof in accordance with the practice of (1) excluding white pixels from the averaging step where the number of white pixels is no more than 50-percent of the group, and (2) excluding non-white pixels from the averaging step where the number of white pixels in the group is greater than 50-percent.