PURPOSE: To provide the image processing method by which a processing object can be extracted as the same processing object, even if uneven brightness or uneven color exists.

CONSTITUTION: From a reference image 101 containing a processing object, a color distribution/extraction distribution 106 whose extraction is desired and a color distribution/obstraction distribution 107 whose extraction is not desired are obtained. A contour of the extraction distribution 106 is approximated by combining enough many color extraction ranges. From this contour, plural adjacent color extraction ranges are selected, synthesized to one color extraction range and the number of color extraction ranges is decreased, but if the synthesized color extraction range collides with the obstruction distribution 107, two of them are not synthesized. The combination of the color extraction ranges whose number is decreased to the number used for the extraction processing is a color distribution extraction range for approximating the extraction distribution 106. In a processing image 112, when an area being a color contained in one of the color distribution extraction ranges is extracted, the processing object having unevenness can be extracted.