| 摘要 |
Acquiring image data for each color component by guiding the reflected light from a read position on a contact glass, to a line sensor for each color component, detecting a provisional foreign matter region in one image data, determining a first condition on the basis of the number of pixels constituting the provisional foreign matter region, determining a second condition on the basis of the average value of the density values of all of the pixels within the provisional foreign matter region when the first condition is satisfied, and determining whether or not foreign matter is present at a read position corresponding to the one color component when the second condition is satisfied on the basis of the density value of the pixel corresponding to the provisional foreign matter region in one other image data and the fourth reference value that has been set in advance. |
