1. An image processing apparatus, comprising: an image retrieving unit that retrieves an image including a symbol; a noise detecting unit that detects noise of the image; a comparative image retrieving unit that retrieves a comparative image that is to be compared with a detection region of the image detected as the noise by the noise detecting unit; and a removing unit that, in accordance with comparison results of the detection region with the comparative image, removes from the image one portion of the detection region excluding the other portion of the detection region where at least part of the symbol included in the image is detected as the noise.