IMAGE PROCESSING APPARATUS

Disclosed are an image processing apparatus and an image processing method, which can efficiently execute a hidden-surface process, a blending process on translucent polygons and a shading process by a light source all in a rendering process. An image processing method for generating image data for displaying a plurality of polygons comprises: a mask generation step of receiving polygon data including position data of the polygons in the display screen, generating first mask data indicating effective pixel areas of the polygons in a display screen and Z values indicating depths in the display screen for respective effective pixels from the polygon data, generating second mask data having, as an effective pixel area, a pixel area having a Z value in the foreground of a Z value of another processed polygon among the effective pixel areas of the first mask data, executing an exclusion operation to delete the effective pixel area of the generated second mask data from the effective pixel area of generated second mask data of another polygon to thereby generate trans mask data, and performing generation of the trans mask data polygon by polygon; and a rendering step of implementing a rendering process on each of the polygons with respect to the effective pixel area, indicated by trans mask data generated in the mask generation step.