A display processing method, comprising: accepting designation of two first control points in a model cross section that is a cross section of a generated model of a heart; setting two second control points in a cross section image of the heart, the cross section image obtained by performing a medical imaging scan of a patient at a reference time, wherein each of the two first control points corresponds to either of the two second control points; first performing a first transformation processing that includes expansion or reduction for the model cross section at the reference time so that the position of the second control points at the reference time is identical to the position of the corresponding first control points, the first transformation processing using scale parameters calculated based on the positions of the first and second control points; second performing the expansion or reduction included in the first transformation processing using the scale parameters at the reference time for a second model cross section at each second time that is a time after the reference time, wherein the second model cross section at the each second time is a cross section of the generated model at the each second time, is the same cross section as the model cross section, and has two third control points whose positions correspond to positions of the two first control points, and each of the two third control points corresponds to either of two fourth control points in a cross section image at the each second time; first superimposing the cross section image at the reference time and a contour of the model cross section after the first transformation processing to display a first superimposition result; third performing a second transformation processing for the second model cross section at a next second time, for which the expansion or reduction included in the first transformation processing was performed, so that a position of one of the two fourth control points in the cross section image at the next second time is identical to a position of a corresponding third control point in the corresponding second model cross section after the expansion or reduction included in the first transformation processing, and another third control point in the second model cross section after the expansion or reduction included in the first transformation processing is on a straight line that passes through the two fourth control points in the cross section image at the next second time; second superimposing the cross section image at the second time and a contour of the second model cross section after the second transformation processing to display a second superimposition result; and repeating the third performing and the second superimposing. accepting designation of two first control points in a model cross section that is a cross section of a generated model of a heart; setting two second control points in a cross section image of the heart, the cross section image obtained by performing a medical imaging scan of a patient at a reference time, wherein each of the two first control points corresponds to either of the two second control points; first performing a first transformation processing that includes expansion or reduction for the model cross section at the reference time so that the position of the second control points at the reference time is identical to the position of the corresponding first control points, the first transformation processing using scale parameters calculated based on the positions of the first and second control points; second performing the expansion or reduction included in the first transformation processing using the scale parameters at the reference time for a second model cross section at each second time that is a time after the reference time, wherein the second model cross section at the each second time is a cross section of the generated model at the each second time, is the same cross section as the model cross section, and has two third control points whose positions correspond to positions of the two first control points, and each of the two third control points corresponds to either of two fourth control points in a cross section image at the each second time; first superimposing the cross section image at the reference time and a contour of the model cross section after the first transformation processing to display a first superimposition result; third performing a second transformation processing for the second model cross section at a next second time, for which the expansion or reduction included in the first transformation processing was performed, so that a position of one of the two fourth control points in the cross section image at the next second time is identical to a position of a corresponding third control point in the corresponding second model cross section after the expansion or reduction included in the first transformation processing, and another third control point in the second model cross section after the expansion or reduction included in the first transformation processing is on a straight line that passes through the two fourth control points in the cross section image at the next second time; second superimposing the cross section image at the second time and a contour of the second model cross section after the second transformation processing to display a second superimposition result; and repeating the third performing and the second superimposing.