| 摘要 |
PROBLEM TO BE SOLVED: To detect a roller mark attached when an image scanner reads a document.SOLUTION: A document image extraction section 11 extracts a document image read by an image scanner 1, a first black prohibition area extraction section 12 extracts from the image an upper black prohibition area, a histogram generation section 13 generates a histogram, and a threshold calculation section 14 calculates a threshold. A first binarization section 15 binarizes the upper black prohibition area by the threshold, and a first noise position detection section 16 detects a noise. In the same manner, a second black prohibition area extraction section 17, a second binarization section 18, and a second noise position detection section 19 detect a noise position of a lower black prohibition area of the document. A noise position comparison section 20 confirms the continuity of the noises in the upper and lower black prohibition areas, and a noise determination section 21 determines whether or not the noises are a roller mark.SELECTED DRAWING: Figure 1 |
