An image processing method includes: forming a density unevenness measurement test image based on image data subjected to unevenness correction processing to correct density unevenness, using a preset unevenness correction value; acquiring a pre-conversion density measurement value that is a density measurement value of each density setting value for every recording element in the density unevenness measurement test image before processing after image formation using a recording head; converting the pre-conversion density measurement value into a post-conversion density measurement value corresponding to a density measurement value after the processing, using a density measurement value conversion value derived beforehand and indicating a conversion relationship of density measurement values before and after the processing for every density setting value and to which the set unevenness correction value is applied as the density setting value; and deriving a new unevenness correction value using the post-conversion density measurement value.