In a photo digitizing system, the date-of-photograph of each individual image is extracted from image data, and is recorded in association with each image data on a storage medium. If the date-of-photograph of a print image cannot be determined based on its own data, a corresponding film image is retrieved by comparing the image data of the print image to image data of each of the film images, and the date-of-photograph of the corresponding film image is determined to be the date-of-photograph of the concerned print image. When the customer adds a tag to any one of the digitized images, data of the tag is recorded in a customer IDX file in relation to a frame number of that image. To retrieve some images from the storage medium by use of a search term, those frame numbers which are related to tag data that match with the search term are extracted in the customer IDX file, so the images having the extracted frame numbers are displayed.