To attain visual ease of additional information by selecting an image with higher visibility than a changing characteristics, in a prescribed area of a recorded image among a plurality of variations, stored of changing characteristics.

The visibility of additional information having a characteristic selected and added on a hard copy image is improved by selecting any of variations storing the changing characteristics with highest visibility of an image of a hard copy. For example, when a width of each horizontal line 165 of a small image is two pixels, a computer analyzes a visible and changing characteristic of a content of a small image, including a horizontal line 165 with a width of four pixels. When most of the thin part in the horizontal direction of the width of four pixels of the small image is red, the color of the horizontal line of this part is changed into a cyan color. One set of the horizontal lines on the small image are visible, and the designated specific film image is identified.