PURPOSE: To minimize a color difference between an original picture and a reproduced picture in all color reproduction areas by identifying whether an input color picture belongs to an area or is in existence in the vicinity of its border and implementing color correction through the use of a coefficient correcting plural sets of masking coefficients selected from the identified information.

CONSTITUTION: Plural sets of prescribed masking coefficients (Mks) are stored to areas A-D of a masking coefficient (Mk) storage means 4. An area identification means 5 and a border recognition means 6 identify which area input color picture data (R1, G1, B1) belong to or are in existence in the vicinity of the border of the area and output the information. An Mk selection means 3 selects an Mk from the means 4 based on the information from the means 5, 6 and an Mk correction means 2 corrects the Mk selected by the means 3 based on the information from the means 6. Furthermore, a masking arithmetic operation means 1 uses the Mk corrected by the means 2 to apply color correction to the data R1, G1, B1 for each picture element and outputs the result. Thus, the color difference between the original picture and the reproduced picture is minimized for all color reproduction areas.