1. An image processing apparatus for extracting images from a continuous image sequence, the image processing apparatus comprising: a storage unit that stores image information about images constituting the image sequence; an image reading unit that reads the image information from the storage unit; an image change amount calculating unit that calculates a predetermined image change amount between at least two images using the image information read by the image reading unit; an image change amount information adding unit that adds information about the image change amount calculated by the image change amount calculating unit to a corresponding image; and an image extracting unit that extracts a preset number of images from the image sequence based on the information added to each image by the image change amount information adding unit, wherein the image extracting unit rearranges the images based on the information added to each image by the image change amount information adding unit, and extracts images from the image sequence, using a result of the rearranging.