| 摘要 |
A gradient direction detection unit 12 detects a gradient direction of values of pixels contained in an area consisting of N×N pixels including a target pixel at the center of the area, where N is an odd number no less than 3; a selecting unit 13 selects N pixels as selection pixels from among the N×N pixels in a direction orthogonal to the gradient direction, the selection pixels including the target pixel; a filter coefficient initialization unit 14 initializes filter coefficients corresponding to the selection pixels respectively; a reference value determination unit 15 determines, for each of the selection pixels, a reference value for correction of the corresponding filter coefficient, based on pixel values of pixels determined by the gradient direction; a filter coefficient correction unit 16 corrects, for each of the selection pixels, an initial value of the corresponding filter coefficient, based on the corresponding reference value; and a pixel value calculation unit calculates an output pixel value of the target pixel, based on pixel values of the selection pixels and corrected values of the filter coefficients. |
