Method for determining a candidate of a branched direction of a linear

Abstract

A linear image is traced on the basis of an instruction to trace the linear image through an image processing system for processing a trace of the linear image of data of an image, having an image memory for storing the data of the image, a data memory for storing data of a graphic, a display unit for displaying the data of the image and the data of the graphic, an input unit for entering the instruction, and a semi-automatic image trace processing section for processing the trace of the linear image on the basis of the instruction. The candidate of the branched direction is detected by tracing the linear image having a line width smaller than a predetermined line width; setting a point on a contour line of the linear image as a first trace base point when the trace detects a branched point at which the line width of the linear image to be traced expands temporarily; transferring the first trace base point on the contour line by a predetermined distance and setting a point existing on the contour line opposite to the contour line on which the first trace base point is located and in the position closest to the first trace base point, as a second trace base point; and detecting a middle point between the first trace base point and the second trace base point as a candidate of the branched direction.