Patent ID: 8170365
Filing Date: 2012-05-01
Classification: G06K,G06T

Abstract:
1. An image processing device comprising: a pixel information output section that reads an image along a predetermined direction, and outputs saturation information expressing the degree of saturation of respective pixels of the image and lightness information expressing the lightness of the respective pixels of the image; a dust pixel extraction section that, on the basis of the saturation information and the lightness information output by the pixel information output section, extracts dust pixels that are candidates for pixels expressing dust existing in the predetermined direction; a lightness-changed pixel extraction section that, on the basis of the lightness information output by the pixel information output section, extracts lightness-changed pixels that express lightness-changed portions; a correction object pixel extraction section that, from among the dust pixels extracted by the dust pixel extraction section, extracts, as pixels that are objects of correction, dust pixels that have not been extracted as lightness-changed pixels by the lightness-changed pixel extraction section and dust pixels in whose vicinities lightness-changed pixels extracted by the lightness-changed pixel extraction section do not exist; a correction section that corrects saturation information and lightness information of the pixels extracted by the correction object pixel extraction section, using saturation information and lightness information of neighboring pixels of the pixels extracted by the correction object pixel extraction section; and an image information output section that outputs image information that includes information expressing pixels corrected by the correction section; wherein the dust pixel extraction section comprises: a first pixel extraction section that, for each of the pixels, compares the saturation of a pixel and a first value, which is determined from respective saturations of a first pixel group that includes pixels aligned sequentially from one of two pixels that are adjacent to the pixel up to a first predetermined number thereof, determines whether or not the saturation of the pixel is separated from the first value by greater than or equal to a threshold value, and extracts the pixel as a first pixel when the determination is affirmative; a second pixel extraction section that extracts, from among pixels aligned sequentially from a pixel that is adjacent to the first pixel extracted by the first pixel extraction section, a second pixel that has a saturation which is not separated from the first value by greater than or equal to a threshold value and that is positioned nearest to the first pixel; and a saturation-changed pixel extraction section that, when a number of intermediate pixels existing between the first pixel and the second pixel is less than or equal to a second predetermined number, extracts the first pixel and the intermediate pixels as saturation-changed pixels, wherein, when the lightness of a saturation-changed pixel, which is extracted by the saturation-changed pixel extraction section, is not darker than the lightness of one of two adjacent pixels and the lightness of the second pixel, the saturation-changed pixel is extracted as a dust pixel.