This invention provides an image processing method which allows easy re-use of image information that is stored to minimize deterioration of image quality and the storage capacity. Storage means is searched for original digital data corresponding to each input image. If no original digital data is found, the input image is converted into vector data, and is stored as digital data in the storage means. A sheet including at least one of information associated with the found original digital data when the original digital data is found in the search step and information associated with digital data which is obtained by converting the image into the vector data in the vectorization step and is stored in the storage step when no original digital data is found in the search step is generated, thus providing a sheet that allows easy re-use.