PURPOSE: To cancel trouble not to express the parts of '.' upside and downside '÷'in a small closed area by dots but to observe '-' in the case of painting out the inside of the contour data of characters or the like.

CONSTITUTION: In a system provided with a storing means 21 to store information for deciding the closed area or the like and a painting-out means 22 to paint out the relevant part of the closed area in a memory 23 (26) for plotting based on the information deciding the closed area, a judging means 24 is provided to judge the intersection of a straight line orthogonal to a scan line for scanning the closed area at prescribed intervals and the scan line is included in the closed area or not, and a plotting means 25 is provided to additionally plot dots expressing the area in a relevant part near the closed area in the memory 23 (26) for plotting when no intersection is included.