| 摘要 |
PROBLEM TO BE SOLVED: To precisely extract a specific image without decreasing the amount of information of an input image by converting an input multi-valued image into different multi-valued information and deciding whether or not the specific image is included according to the multi-valued information. SOLUTION: The image processor is equipped with a density conversion part 10 which performs density conversion by pixels of an input image from a scanner, etc., and a decision part 20A which decides whether or not the image outputted from the density conversion part 10 includes a specific image. The density conversion part 10 converts the density of 9 pixels (center pixels and 8 surrounding nearby pixels) and performs different density conversion by Aij (i=0 to 2, j=0 to 2) components linked with the pixel positions. For example, a density converting process based upon a certain density conversion curve is performed for the pixel corresponding to A00 and a density converting process based upon a different density conversion curve is performed for the pixel corresponding to A01 . |
