Image processor for detecting specified pattern

摘要

In an image processor, it is decided that a target pixel has a specified color when the input color data of the pixel are decided to exist in the first ranges and the differences between color data of the pixel and those of pixels adjacent thereto are decided to exist in the second ranges. Thus, the specified color in a specified pattern can be detected even when the input image data are affected by external factors. Alternatively, it is decided that the pixel has a specified color when the input color data of the pixel are decided to exist in the first ranges and the results of calculation on the input color data are decided to exist in the second ranges. Errors in color detection can be decreased by narrowing the color detection ranges with use of different types of conditions.