| 摘要 |
PROBLEM TO BE SOLVED: To surely discriminate a line drawing and images other than the line drawing and to reduce the memory capacity by classifying image data into white, black and data other than white and black data, so as to extract an edge of the line drawing. SOLUTION: RGB data, received by a line drawing recognition section 301, are given at first to a monochromatic processing section 303, where the data are converted based on luminance, density or G data into monochromatic data. A Laplacian section 304 extraction an edge of a line drawing and detects white and black areas. That is, for the case that a plurality of white/black level pixels exist around a white/black level pixel and the change in the density of the surrounding pixels is a prescribed value or below, the white/black level pixel is detected within a white/black level pixel area. A pattern-matching section 305 A extracts a white area around the black area to extract an edge of a thick line part of the line drawing. A pattern-matching section 305 B extracts thin lines and extracts it as a thin line when both sides of a black pattern are inserted by white patterns. |
