1. A medical image processor for correlating and analyzing at least two comparison images, comprising: means for substantially simultaneously displaying said two comparison images; means for setting at least one reference point in one of the images; means for setting a correlation detection area related to said at least one reference point in the other image; means for obtaining and calculating a degree of correlation between image information of said at least one reference point and image information of each point in said detection area; means for displaying a plurality of numerical values representing the degree of correlation in a rectangular correlation table, the plurality of said numerical values being arranged in a one-to-one correspondence with respect to each point in the detection area; image movement means for relatively moving said two comparison images so that the image information of said at least one reference point coincides with image information of a corresponding point represented by a maximum numerical value in said correlation table, said means for obtaining and calculating a degree of correlation and said image movement means being operable alternately and repeatedly; and decision means for deciding a coincidence between the image information of said reference point and the image information of the corresponding point.