Image distinguishing device.

摘要

This invention relates to an image distinguishing device for distinguishing a area surrounded by a marker line (for instance, drawn by a half-tone marking pen) of half tone area on a document image and can be preferably utilized for trimming or masking on the document image, for example, in a digital document copying machine or a facsimile. In the image distinguishing device, the reading data of a document image is binarized with two mutually different threshold values (for instance, the bits corresponding to the white and black area are classified as "0" and bits corresponding to the half tone area are classified as "1"). And the starting point and terminating point of the marker line for each of the scanning lines are detected from the binarized data and the one-dimensional marker line is detected for each line. Continuously, the leadingness and the consecutiveness of the marker line pertaining the plane of the document is distinguished from the mutual relationship of the one-dimensional marker line for each of the lines as shown in the above. And the area surrounded by the two-dimensional marker line is detected.