| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technology for reducing noise while an edge with low contrast is preserved. <P>SOLUTION: The number H of pixels having the same pixel value as a pixel value x of a target pixel is obtained from pixel values of peripheral pixels of the target pixel. The number H1 of pixels having a pixel value which is the closest to the pixel value x of the target pixel among the pixel values smaller than the pixel value x of the target pixel is obtained from the pixel values of the peripheral pixels. The number H2 of pixels having a pixel value which is the closest to the pixel value x of the target pixel among the pixel values larger than the pixel value x of the target pixel is obtained from the pixel values of the peripheral pixels. Then, a=(H2-H1)/(2×H) is calculated. Then, σ<SP POS="POST">2</SP>=C1×I+C2 is calculated by using coefficients C1 and C2 by setting an average pixel value of the pixel value x, or the pixel values of the target pixel and the pixels of the peripheral pixels is set to I. The pixel value x of the target pixel is updated to (x+a×σ<SP POS="POST">2</SP>). <P>COPYRIGHT: (C)2012,JPO&INPIT |
