Patent ID: 6614943
Filing Date: 2003-09-02
Classification: H04N

Abstract:
A method of binary coding a multi-gradation input image, said method comprising the steps of:(a) binary coding a first color corresponding to a target pixel so that at said target pixel said first color is one of ON and OFF; and (b) binary coding a second color at said target pixel to OFF if said first color has been binary-coded to ON, the first color being black and being represented by K, and when K is binary coded to OFF, each of a plurality of remaining colors to be binary coded is processed one by one in an order of highest to lowest density, the order of highest to lowest density being determined based on an input image including each of the remaining colors, when a color that is processed following K is binary coded to ON, a threshold value above which remaining colors are binary coded to OFF is decreased for each of the then remaining colors to be binary coded, and when the color that is processed following K is binary coded to OFF, a threshold value above which at least one of the remaining colors is binary coded to ON is decreased for each of the then remaining colors.