JPS6470890A - Method for writing contour of graphic - Google Patents

Abstract

PURPOSE:To improve the efficiency of primitive writing and that of recognition processing by forming a contour tracing part, a curvature calculating part and a primitive writing part, detecting a rugged point based on the curvature of adjacent three points with equal intervals on a contour and dividing the contour into respective sections. CONSTITUTION:The contour of an input binary image is traced by the contour tracking part 1 to find out the coordinates of the contour and the curvature calculating part 2 finds out curvature from the outline. The 1st primitive dividing part 3A in the primitive writing part 3 detects the rugged part of the contour from the curvature values of the adjacent three points with equal intervals on the contour and divides the contour into respective sections (primitives) at the rugged part. The average value of the curvature values in each divided section is found out and compared with a threshold for discriminating a straight line from a circular arc. As the result, a linear primitive and an arc primitive are decided, calculations are respectively executed by respective prescribed equations, the coordinates of an intersecting point between the remarked primitive and its adjacent primitive and the coordinate of a vertex are found out and then the length of each primitive is found out. Consequently, the efficiency of primitive recognition and the efficiency of writing can be improved.