1. An X-ray analysis apparatus converting an X-ray intensity distribution of discrete data determined for each pixel, from a first plane where the distribution is known into a second plane where the distribution is not known, the analysis apparatus comprising: a projection section projecting, onto the second plane, a grid point which specifies a pixel on the first plane and an intermediate point between the grid points, as nodes; an occupancy ratio calculation section calculating an area of a region where a polygon expressing a projected pixel specified by the projected nodes overlaps with each pixel on the second plane, to thereby calculate an occupancy ratio of the polygon expressing the projected pixel to each pixel on the second plane; and a conversion section distributing X-ray intensity in a pixel on the first plane to a pixel on the second plane based on the occupancy ratio, to thereby convert the X-ray intensity distribution.