In a pipeline process in which plural image processing sections (image processing modules), for example, an image inputting section 131, a histogram producing section 132, and a binarizing section 133 are connected in a pipeline manner, each of the image processing sections 131, 132, and 133 is provided with a function of reinitializing a state to cause each process to be again performed with being started from the beginning of an image, whereby image data to be processed can be reread.