DRAWING DEVICE, AND METHOD FOR REPRESENTING DEPTH OF FIELD BY THE DRAWING DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain the method for representing the depth of field showing a feeling of the distance from a viewpoint to an object on a two-dimensional screen by putting the image part of the object corresponding to a Z value just in focus and other image parts of the object out of focus. SOLUTION: An image (original image) in a VRAM drawing area 501 is reduced to a half in steps in work areas 503 to 505 to generate images of target resolution of (1/2)n+1 of the original image. Thus, the images of target resolution are outputted to the original VRAM drawing area 501 by applying pixel interpolating algorithm. At this time, a proper value is set as the Z value and then only pixels deeper than the Z are overwritten with images of lower resolution to obtain an image which is out of focus inside the Z as a border. Namely, the image can be generated which represents the object with the Z value just in focus and increases inwardly in defocusing degree in order with the distance from the Z value.