Patent ID: 8189236

Claim:
An image processing apparatus comprising: a first edge extracting unit that extracts an edge of chromatic components of a color image other than brightness components of the color image; and a binarizing unit that performs an enhancement process and a binarization process for pixels being extracted as the edge by the first edge extracting unit and performs the binarization process for pixels other than the pixels being extracted as the edge based on the brightness components; and a second edge extracting unit that extracts an edge of the brightness components of the color image; a brightness binarizing unit that binarizes the brightness components of the color image; a first synthesizing unit that synthesizes an image being binarized by the brightness binarizing unit and pixels being extracted as the edge by the second edge extracting unit, wherein the first synthesizing unit handles the pixels, which are extracted as the edge by the second edge extracting unit, as one of two given values; and a second synthesizing unit that synthesizes an image synthesized by the first synthesizing unit and the pixels being extracted as the edge by the first edge extracting unit, wherein the second synthesizing unit handles the pixels, which are extracted as the edge by the first edge extracting unit, as the one of the two given values, if, in the image synthesized by the first synthesizing unit, a certain number or more of pixels having the one of the two given values exist around a pixel having the one of the two given values and being extracted as the edge by the first edge extracting unit, the second synthesizing unit does not set the one of the two given values to the pixel, which has the one of the two given values in the image synthesized by the first synthesizing unit and is extracted as the edge by the first edge extracting unit, in an image synthesized by the second synthesizing unit, and the binarizing unit represents the image synthesized by the second synthesizing unit, the binarization process being performed by the binarizing unit includes a pseudo halftone binarization process, and the binarizing unit performs the enhancement process and then performs the binarizing process for pixels that have the other of the two given values in the image synthesized by the second synthesizing unit and have the one of the two given values in the image synthesized by the first synthesizing unit.