PICTURE GENERATING DEVICE

摘要

PURPOSE:To accurately know the position and the area of a polygon included in a single picture element by inserting a subscan line vertically to a horizontal scan line to scan only the height of a single picture element and then scanning immediately only the necessary picture elements. CONSTITUTION:A vertical scanning position deciding part 2 detects the positions of the apexes of a polygon, the intersecting point between edges, and the intersecting point between a scan line and the edge by noticing only the picture elements including the polygon apexes, the intersecting point between edges, and the intersecting point between the scan line and the edge that cause the errors at calculation of the polygon area. Then a horizontal scan line of a horizontal scan part 1 and a vertical subscan line of a vertical scan part 3 are inserted in a single picture element for scan of the picture elements. Thus the position and the area of a polygon can be accurately known within a single picture element in a small processing quantity.