Patent ID: 6185006
Filing Date: 2001-02-06
Classification: G06K,H04N

Abstract:
A method for converting a continuous tone image into a pseudo-halftone image, the method comprising the steps of:receiving data of a continuous tone image desired to be converted into a pseudo-halftone image, the continuous tone image having a plurality of pixels, each pixel having one density value defined in a range between a predetermined minimum density and a predetermined maximum density; andsubjecting all the pixels of the continuous tone image to an error-distributing binary conversion process on a pixel by pixel basis along a main scanning direction, to thereby convert the density values of the pixels into binary values while calculating binary conversion errors and distributing the calculated binary conversion errors to neighboring pixels, while performing at least one of a first converting process and a second converting process, the first converting process being for compulsively converting a minimum density pixel that has the minimum density into a first binary value and adjusting a binary conversion error produced for the minimum density pixel into a non-uniform error value, the second converting process being for compulsively converting a maximum density pixel that has the maximum density into a second binary value and adjusting a binary conversion error produced for the maximum density pixel into another non-uniform error value.