Patent ID: 7660018
Filing Date: 2010-02-09
Classification: G06T,H04N

Abstract:
1. An image reading device comprising: a document carrying part that carries a document along a carrying path; a reading part that reads an image at a reading position which is decided ahead of time along the carrying path and outputs image data expressing the image; a first dust detecting part that compares pixel values of the image data, which is output by the reading part when the document is not at the reading position, with a prescribed threshold and generates a first dust detection data indicating positions of pixels which are affected by dust; a second dust detecting part that compares pixel values of the image data, which is output by the reading part while the document is passing the reading position, with a prescribed threshold and generates a second dust detection data; a third dust detection part that generates, in a case in which dust is indicated as being present at a matching position in a main scanning direction in both the first dust detection data and the second dust detection data, a third dust detection data which indicates the position of that dust, the second dust detection data being independent from the first dust detection data by virtue of the second dust detection data representing pixel values of image data while the document is passing the reading position and the first dust detection data representing pixel values of image data while the document is not at the reading position; a noise judging part that judges that noise is present in a case in which the third dust detection data indicates that dust is continuously present for at least a prescribed length in a sub scanning line direction; and a process executing part that executes a process which has been decided upon ahead of time in a case in which noise is judged to be present by the noise detecting part.