| 摘要 |
A noise filter is provided to effectively detect/suppress noise occurring in a boundary part of an image having a large shading difference. A boundary determining unit determines a boundary location of shading by pixel values of peripheral pixels. A selection filter unit performs filter processing within a range of pixels which do not belong to the determined boundary among the peripheral pixels. A differential absolute value between a target pixel and a 8 or 24 pixel average value around the same color is calculated(S101,S102,S107). When the differential absolute value is larger than a threshold value, each differential absolute value of the target pixel and vertical/horizontal/diagonal average values of 8 or 24 pixels is calculated. A value of the target pixel is replaced with an average value corresponding to the minimum value among the differential absolute values(S112,S113,S114). |
