Patent ID: 8077966

Claim:
A binarizing device comprising: a difference vector calculation unit that, in a case where each pixel of a color image is made to be a current pixel in order and a region, which has a predetermined size and includes the current pixel, is set to be a peripheral pixel region, calculates a difference vector between an average color of the peripheral pixel region and a current color of the current pixel; a selection unit that selects one of the average color and the current color as a significant color; and an output unit that, in a case where the following conditions (1) and (2) are satisfied, outputs one of binary values, and that, in a case where at least one of the following conditions (1) and (2) is not satisfied, outputs the other of the binary values: (1) a length of the difference vector is not less than a predetermined value; and (2) the selection unit selects the current color as a significant color, wherein the selection unit calculates a run length of each of the average color and the current color in a plurality of directions in the peripheral pixel region, and selects one of the average color and the current color, which has a shorter run length, as the significant color.