| 摘要 |
PURPOSE:To eliminate the need for the discrimination with a man, by obtaining the distribution of generation of frequency for a difference between adjacent representative density values, in a rectangular region cut out from a reading picture, and discriminating a line drawing region based on the distribution. CONSTITUTION:A digital picture is sectioned into meshes of MXM picture elements. The average density of picture elements at each mesh is obtained and the obtained average density is determined as the representative density of this mesh. In the entire set of each representative density, the picture to be read in is cut out into a rectangle. In the cut-out rectangular region, the distribution of frequency of generation of an absolute value of the difference between adjacent representative density values toward the main and sub-scanning direction is formed. When the frequency of generation of (0) of the difference between representative density values is more than the estimated threshold value both for the main and sub-scanning directions, this rectangular region is discriminated as a line drawing region. The processing is repetitively done for the entire set of each representative density value. |
