Depth of Field Postprocessing For Layered Scenes Using Constant-Time Rectangle Spreading
Control over what is in focus and what is not in focus in an image is an important artistic tool. The range of depth in a 3D scene that is imaged in sufficient focus through an optics system, such as a camera lens, is called depth of field. Without depth of field, the entire scene appears completely in sharp focus, leading to an un- natural, overly crisp appearance. Current techniques for rendering depth of field in computer graphics are either slow or suffer from artifacts, or restrict the choice of point spread function (PSF). In this paper, we present a new image filter based on rectangle spread- ing which is constant time per pixel. When used in a layered depth of field framework, our filter eliminates the intensity leakage and depth discontinuity artifacts that occur in previous methods. We also present several extensions to our rectangle spreading method to allow flexibility in the appearance of the blur through control over the PSF.
Todd J. Kosloff, Michael W. Tao, and Brian A. Barsky. "Depth of Field Postprocessing For Layered Scenes Using Constant-Time Rectangle Spreading". In Graphics Interface, May 2009.