| 摘要 |
<P>PROBLEM TO BE SOLVED: To exactly detect existence of dust at a reading position of an original and to remove a noise image resulting from the dust from a read image. <P>SOLUTION: A dust detection circuit 11 extracts pixels below the prescribed number having density deviated more than a threshold from density of a group of pixels existing within a prescribed range from a position of the self-pixel below the prescribed number and continuously arranged in a scanning line as abnormal pixels based on density of the respective pixels included in image data when the image data are the one output in a period when the original is not at the reading position. In addition, the dust detection circuit 11 extracts the pixels under the prescribed number having density deviated more than the threshold from the density of the group of pixels existing within the prescribed range from the position of the self-pixel and continuously arranged in the scanning line as the abnormal pixels based on density of the respective pixels obtained by performing gamma correction to the image data by a gamma correction circuit 8 when the image data are the one output in a period when the original passes through the reading position. <P>COPYRIGHT: (C)2008,JPO&INPIT |
