| 摘要 |
PROBLEM TO BE SOLVED: To prevent an image quality from becoming nonuniform in accordance with a direction in comparison with a configuration where a degree of edge emphasis is made equal regardless of a scan direction, in the case where there is a resolution difference dependent on the scan direction when reading a document image.SOLUTION: In a first filtering section 156, while utilizing a principal of filtering, image quality reduction (blurring or bleeding) dependent on a resolution difference between a main scan direction and a sub scan direction is corrected by a window in which an edge emphasis degree of a filter coefficient in the main scan direction where the image quality reduction is relatively high, is strengthened rather than that of a filter coefficient in the sub scan direction where the image quality reduction is relatively low. The window defines a window to which a numerical value of the filter coefficient is set as a band pass filter, as a reference window. The filter coefficients are made different between the main scan direction and the sub scan direction while defining a pixel of interest as a reference in the band pass filter. Thus, edge emphasis processing is executed on a specific band and it is known that the edge emphasis degree in the main scan direction is stronger than that in the sub scan direction. |
