| 摘要 |
<P>PROBLEM TO BE SOLVED: To extract and encode ruled lines from document image data. <P>SOLUTION: Binary document images are acquired and connecting pixels are recognized from the images. The periphery lengths of the connecting pixels are found, the connecting pixels with larger periphery length than a predetermined threshold THC are determined to be the ruled lines, and the ruled lines are solely extracted. When setting the threshold value THC, the connecting pixels in the document images are stored, the number of pixels with the periphery length for every periphery length for each stored connecting pixel is counted, the local maximum point (x<SB>m</SB>', y<SB>m</SB>') as the farthest point from the straight line connecting a point (x<SB>1</SB>, y<SB>1</SB>) in the rank of the smallest periphery length and a point (x<SB>N</SB>, y<SB>N</SB>) in the rank of the largest periphery length in the relation between the periphery lengths and the number of pixels is found, and the periphery length of the local maximum point is set as the threshold value THC. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
