| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide edge enhancement and a noise reduction effect in accordance with image features, and to adjust an image of characters and lines in particular to a clearer image by enhancing edges. <P>SOLUTION: A pixel extracting part 201 extracts a 5x5 pixel block around an arbitrary pixel of interest. A brightness calculation part 202 calculates a brightness degree of each pixel in the pixel block extracted by the pixel extracting part 201. A standard deviation calculating part 203 calculates a standard deviation value in a difference of a brightness degree between the pixel of interest and each of the other pixels. A filter processing part 204 uses the standard deviation value calculated by the standard deviation calculating part 203 to perform filter processing of an inverse Gaussian distribution form of a bilateral filter, a Mexican hat filter, a lowpass filter and a highpass filter with a filter, etc., having a filter coefficient weighted by the standard deviation, and outputs an image. A pixel having a large standard deviation value is regarded as a pixel of a character and a line and is subjected to such filter processing that enhances high frequency components to enhance edges. <P>COPYRIGHT: (C)2010,JPO&INPIT |
