Programmable GPU based real-time simulation of depth of field

The prominent characteristic of an image with depth of field (DOF) effect is that part of the image is clear but the other part is blurry. From this point, in the computer simulation of DOF, an image of the three-dimensional scene was produced and it was stored as a texture which was called as clear scene-texture. In the process of imaging, the information of the depth of objects was stored in the alpha channel by vertex program. Then the clear scene-texture was filtered averagely several times and another blurry scene-texture was got. At last, the alpha value stored in the clear scene-texture was taken as the coefficient, which used it to blend these two textures to achieve the DOF effect. The algorithm takes extensive use of the Graphics Processing Unit (GPU) for its multi-texture and programmable performance, and thus transfers the considerable calculation from the CPU to the GPU. The algorithm can well simulate the real-time DOF effect, and can be applied in VR system.