According to an embodiment, provided is an image processing system that includes: a light source that emits light; an imaging unit including an imaging element that captures light emitted and reflected from a foreign matter attached to the other surface of the transparent member and that captures light transmitted through the transparent member from the other surface side; and an image analyzing unit that analyzes captured image data. The captured image data is formed of a first image area frame used for detecting a foreign matter, and is formed of a second image area frame that corresponds to an effective imaging area excluding a predetermined area. Different rules are applied to read pixel data of between the first image area frame and the second image area frame.