Patent ID: 7009735

Claim:
A method for performing black trapping on image data from a raster image processing frame buffer, wherein the image data includes pixel data according to a predetermined color space and black rendering hints, the method comprising the steps of: a) receiving the pixel data and the black rendering hints from the frame buffer, b) converting the pixel data from the frame buffer to device color space (e.g C,M,Y,K) data, c) retrieving the C,M,Y,K data and an associated black rendering hint for a first pixel; d) determining if the black rendering hint for the first pixel is true, e) if the black rendering hint is true, performing a black trapping algorithm using a plurality of pixels forming a context window associated with the first pixel and subsequently rendering the first pixel according to an under print system, otherwise, subsequently rendering the first pixel according to a default rendering system; f) determining if additional pixel data from the frame buffer is to be processed in accordance with steps c) through e); and, g) if additional pixel data is to be processed, repeating steps c) through e) for a next pixel, otherwise, ending the process.