发明名称 Contrast enhancement using gradation conversion processing
摘要 A non-transitory computer-readable storage medium storing an image processing program causing a computer to execute an image processing on image data to be processed, the image processing program including an obtaining step obtaining the image data, a gradation conversion processing step performing gradation conversion processing on the image data at an intermediate part of gradation according to input/output characteristics having characteristics to which characteristics to reduce a contrast are added, and a correcting step making a correction to enhance a local contrast indicative of contrast at a local part of an image for the image data subjected to the gradation conversion processing by using a gain curve in which a degree of enhancement changes in accordance with luminance information of a pixel to be processed, and thus, bright and dark part gradations are improved while suppressing a change in a hue and color saturation as well as maintaining an apparent contrast.
申请公布号 US8989510(B2) 申请公布日期 2015.03.24
申请号 US201113086868 申请日期 2011.04.14
申请人 Nikon Corporation 发明人 Muramatsu Masaru
分类号 G06K9/40;H04N1/407;G06T5/00;H04N1/60;H04N5/232 主分类号 G06K9/40
代理机构 Oliff PLC 代理人 Oliff PLC
主权项 1. A non-transitory computer-readable storage medium storing an image processing program causing a computer to execute an image processing on first image data to be processed, the image processing program comprising: an obtaining step obtaining the first image data; a gradation conversion processing step performing a gradation conversion processing on the first image data obtained by the obtaining step at an intermediate part of gradation by a gradation curve having characteristics to reduce a contrast; a low pass processing step generating second image data by performing a low pass processing on the first image data on which the gradation conversion processing is performed in the gradation conversion processing step; and a correcting step making a correction to the first image data on which the gradation conversion processing is performed in the gradation conversion processing step by a gain curve having characteristics to increase a luminance value when a luminance value of the first image data is larger than a luminance value of the second image data and to decrease the luminance value when the luminance value of the first image data is smaller than the luminance value of the second image data by comparing the luminance value of the first image data on which the gradation conversion processing is performed in the gradation conversion processing step with the luminance value of the second image data, wherein a gradient of the gain curve is higher when the luminance value of the first image data is smaller than the luminance value of the second image data than when the luminance value of the first image data is larger than the luminance value of the second image data.
地址 Tokyo JP