IMAGE PROCESSOR, ITS METHOD AND PROVIDING MEDIUM

PROBLEM TO BE SOLVED: To more quickly generate picture data by a ray tracing method. SOLUTION: The image processing method divides an object 53 into plural triangles 53-1 to 53-6 instead of tracing by the 1st ray of a ray tracing method, respective triangles 53-1 to 53-6 are projected to a screen 52 and data on three- dimensional coordinate space are converted into data in the coordinate system of the screen 52. Pixel data in each triangle in the screen coordinate system are interpolated and generated from the data of three vertexes of the triangle. The interpolated and generated pixel data are corrected by tracing based on a 2nd ray.