There has been a problem in that original image data should be saved with another name so as not to be altered, resulting in complexity and an increase in necessary storage region. Image data are housed in a folder managed as a film metaphor and a database of photographic data 30b corresponding to each image data is prepared. When a desirable image processing is selected for desirable image data, the selected image processing is updated as modification information in the database structure. When display, output or print is actually required, various image processings are executed by referring to modification information on only a work area with original image data left. Therefore, it is possible to easily enjoy image modification or the like with the original image data left as they are.