PURPOSE: To extract a character image with high accuracy by forming the graphic of a vector in which image information is converted to a core line, scheduling a necessary graphic consisting of continuous vectors, as a character part, erasing image information extended from the outside of an area, and using the image information which has been erased, as an image of one character.
CONSTITUTION: A vector conversion processing part 2 generates an image converted to a core line, from image information stored in an image memory 1, generates vector information therefrom, and stores it in a vector memory 3. A character area setting processing part reads out the vector information, regards the graphic for satisfying a prescribed condition such as its size, etc., as a character, at every graphic consisting of continuous vectors, sets the smallest rectangle for surrounding a vector graphic, as an area for the image information extraction processing of its character, and informs it to an image processing part 5. The image processing part 5 sets a rectangle extending the area of a prescribed width, to the periphery of the informed rectangle, and the image information extended continuously from the outside periphery to the inside is regards as a part of other graphic than the character and erased. Thereafter, the remaining image information becomes the image information of one character.