To change a gamma curve to be matched with respective objects.

An inputted image is divided into four first division regions, and presence or absence of re-change of a gamma correction curve is individually determined on respective images of the four first division regions. When the gamma correction curve 501 of the image in the first division region is to be changed, for example, presence or absence of overlapping of an input luminance change range R1 of the changed gamma correction curve 502 and a boundary part luminance distribution 701 of the first division region is determined. When the overlapping L exists, the gamma correction curve 502 is re-changed to a gamma correction curve 702 so that the overlapping L is eliminated. The re-changed gamma correction curve 702 is set to be the gamma correction curve of the image in the first division region.