To realize characters of high quality on processed picture data in a magnifying/reducing device for picture data including characters.

At the time of magnifying/reducing picture data Sorg including characters (a), the magnifying/reducing device 30 to which picture data Sorg is inputted magnifys/reduces only a picture (b) with a desired magnifying/ reducing ratio after recognizing and erasing the characters (a) on the picture data Sorg at first, but does not magnify/reduce the character (a). Then, the magnifying/reducing device 30 generates a character picture (a') by selecting a character in a size corresponding to the magnifying/reducing ratio of the picture (b) from a dictionary II37 provided in the magnifying/reducing device 30 and composites it with a magnify/reduced picture (b') to output as processed picture data S'.