| 摘要 |
PROBLEM TO BE SOLVED: To detect a foreign substance image caused by floating dust on a document glass to reduce manufacturing costs even when a sensor having a simple configuration is used, and detects a foreign substance image caused by dust more accurately than before.SOLUTION: A determination unit 102 determines, when a changing pixel detection unit 101 detects changing pixels having a larger amount of change compared with adjacent pixels at a single main scan direction position, that an image indicated by the changing pixels is a foreign substance image for each of an image in which an image reading unit has read a white guide member through a document glass and an image in which the image reading unit has read a document conveyed by a document conveying unit in succession to the reading. |
