The invention provides an image processing apparatus and an image processing method. A specific color detecting section 1 includes: a comparing section 7 for comparing, with reference thresholds, color densities of color image data of plural colors in input image data, so as to judge whether or not the input image data include color image data of a specific color of an image pattern; and a threshold setting section 51 for setting calculated thresholds or theoretical thresholds as the reference thresholds, wherein the threshold setting section 51 a calculated threshold as a reference threshold if the calculated threshold is within an allowable range of the theoretical threshold, and the threshold setting section sets a theoretical threshold as a reference threshold if the calculated threshold is out of the allowable range of the theoretical threshold, the threshold setting section being configured to calculate out the calculated thresholds for the reference thresholds from reference image data obtained by reading out a reference chart having plural colors in predetermined color densities, and the threshold setting section being configured to work out the theoretical thresholds for the reference thresholds according to the predetermined color densities of the reference chart. Thus, in a configuration that uses thresholds, which are calculated from the image data of the reference image data, so as to judge whether or not the input image data are image data of a specific image, it is possible to make an accurate judgment even in a case where the reference image has a problem such as unevenness in color densities, stain, or the like.