Depth of field synthesis using ray tracing approximation

Abstract

Techniques are disclosed for synthesizing depth of field effects in a digital image using ray tracing approximation. For each target pixel in the image, an aperture-shaped kernel is centered about a reference pixel. A cone of rays is traced through the aperture toward the image scene. The trajectory of the rays and the intersections between the rays and objects in the scene are approximated for a given scene depth, focal depth and aperture shape. The color of the pixel lying at the intersection, which may be offset from the target pixel, is sampled. This sampling process is repeated for several apertures bounding the target pixel, where each aperture is centered about a different reference pixel. The resulting color of the target pixel is acquired by integrating the colors of the pixels at each of the resulting intersections.