PURPOSE: To fill the inside of an area surrounded by arbitrary lines with arbitrary patterns in a short processing time by reading the pattern at a position corresponding to a scan position in a second direction from a second storage means while scanning the contour information of a graphic stored in a first storage means in a first direction.

CONSTITUTION: Corresponding to a command for graphic processing inputted from an input device 2 (or a host computer 9), a control part 1 extends the pattern composed of dots inside a memory 5. An image output device 6 as an output device in a raster scan system outputs the contents of the image memory 5. Moreover, an image memory 4 is a memory for storing only the external frame of a closed curve and a pattern memory 7 is provided with a character generator expressing the pattern. A write pen 3 can indicates the inside of the closed curve outputted to the image output device 6 and as a result, the pattern generated by the pattern memory 7 can be generated, erased or changed inside the closed curve or the color or its luminance can be changed.