| 摘要 |
PURPOSE:To quickly and surely detect an erase point by setting a mask for each erase point candidate point obtained from a line cumulative image and using this mask to detect the erase point. CONSTITUTION:Edge information is extracted from the image, which is picked up by an image pickup part 201, by an edge calculating means 100 to calculate the direction of the edge. Lines are generated on the basis of this calculated edge direction by a line generating and accumulating means 101 and are accumulated as a line cumulative image. Erase point candidates are calculated in accordance with the accumulated line cumulative image by an erase point calculating part 213. A mask is set for each calculated erase point candidate point by an erase point detecting means 102, and the erase point candidate point of which the variance of the number of lines passing each side of the mask is smaller than a prescribed threshold and the total sum of lines passing respective sides of the mask is a maximum value is detected as the erase point. |
