| 摘要 |
PROBLEM TO BE SOLVED: To provide an image reading method capable of reading a low density character so that a black streak does not occur at the peripheral edge part of a pasted sheet on a scissors-and-paste original. SOLUTION: A quaternarizing part 12 converts image data outputted from an image reading part 11 into quaternarizing pixel data for extracting a high density character pixel,, a low density character pixel, a high density ground pixel and a low density ground pixel and they are stored in an image line buffer memory 13. A character pixel extracting part 14 extracts a candidate pixel which belongs to a character part but has possibility to pick up the pixel which belongs to the black streak in the peripheral edge part of the pasted sheet. A patch shadow removing part 15 detects the black streak candidate pixel of the patch peripheral edge part by a low density character pixel detecting part 7 and a peripheral range ground detecting part 16 decides the representative ground of a peripheral area by majority concerning the numbers of low and high density ground pixels in the peripheral area of the black streak candidate pixel. A shadow are detecting part 18 detects the shadow area comprising the black streak in the patch of paper peripheral part from the output of the detecting part 16 and outputs a result obtained by removing the shadow area.
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