| 摘要 |
PURPOSE:To improve processing efficiency by making a raster scan in a rectangular area which is circumscribed with the outermost border line at the time of painting-out processing. CONSTITUTION:An image memory 4 is provided which has 2-bit/one-picture- element capacity for storing border picture elements constituting a diagram. Then outside and inside border lines of the diagram are written as certain picture element values in the memory 4 and then picture element values different from those inside and outside border lines of this diagram are written in an area which is one picture element outside the outside border line and an area which is one picture element inside the inside border line. Then the circumscribed rectangular area of the diagram is found and the values of two picture elements succeeding in a horizontal scanning line direction are checked to paint out the given diagram. Consequently, the digital diagram where the outside and inside border lines do not overlap is painted out completely at a high speed. |
