PROBLEM TO BE SOLVED: To discriminate different tissues when displaying a series of medical images in a time sequential order for instance.SOLUTION: A location alignment unit 30 associates pixel locations of three-dimensional volume data 100 composing a three-dimensional volume data set 110 by location aligning pixel locations between the three-dimensional volume data 100. A conversion unit 40 selects a color template 120 including a two-dimensional lookup table formed by setting a first signal value to be a reference to a first axis X, a second signal value for which the first signal value is changed to a second axis Y and a color (R, G, B) and opacity for the first and second signal values to a third axis Z, and converts the signal values of the respective pixel locations of all the three-dimensional volume data 100 to display pixel values by the selected color template 120.
