In order to carry out an image processing with high precision by using a simple structure, an image processing apparatus is provided with an input unit, a storage unit, a binarization unit, and a determination unit. The input unit inputs image data of an image. The storage unit stores a first condition on absolute positions of pixels in the image and a second condition on positions of pixels relative to a target pixel. The binarization unit binarizes the target pixel based upon a color data of the target pixel and that of at least one related pixel to the target pixel to generate a binarized value. The at least one related pixel in the image satisfies the first and second conditions. The determination unit determines whether or not the image has a specified pattern, based upon the binarized values.