A position deviation order detection method according to the invention calculates a difference between input image data of an original image used for printing an image using an inkjet printer and output image data acquired by reading the image using a scanner for each pixel, and compares the calculated difference with a first threshold value to extract pixels for which the difference is equal to or larger than the first threshold value, and detects the size of a position deviation of the image by the number of pixels of a closed pixel group among the extracted pixels.