Edge contrast adjustment filter

摘要

Disclosed herein is a method that includes a classifier that distinguishes objects based on their color shades. A moving window based operator looks at the color class of the adjacent objects and determines if an adjustment is necessary. If at least one of the objects is the type of interest and the color classes of the objects meet the criteria, then the boundary between the objects is subject to be adjusted. Two adjustment modes are discussed: “adjust-tagging” mode and “adjust-color” mode. In the adjust-tagging mode, a specific tag is sent down to the print engine to force the use of high addressability halftones for the boundary pixels in the darker object. In the adjust-color mode, a color lighter (usually white) than that of the lighter object is assigned to the boundary pixels in the lighter object. The width of the modified pixels along the boundary is configurable.

主权项

1. An image processing method for producing objects with enhanced halftone edges, the method comprising:
scanning with a scanner a digital image having a plurality of objects to obtain scanline data; applying by an image processor an edge enhancement filter to the scanline data, including:
classifying each object into a set of shade classes,adding objects tagged as being associated with a first shade class to an event list, andadjusting a parameter if the added object is adjacent to an object classified in a second shade class; generating an output format that includes contone and tag/hint planes; and compressing the output format and sending the compressed output format to a printing system.