| 摘要 |
A method and graphics system capable of super-sampling and performing real-time convolution to form a soft-edge alpha key are disclosed. In one embodiment, the computer graphics system may comprise a graphics processor, a sample buffer, and a sample-to-pixel calculation unit. The graphics processor may be configured to receive 3D graphics data comprising a plurality graphics primitives and then generate a plurality of samples from the 3D graphics data. The samples may comprise both color and alpha information. The super-sampled sample buffer may be coupled to receive and store the samples from the graphics processor. The sample buffer may also be configured to double-buffer at least a portion of each stored sample. The sample-to-pixel calculation unit may be coupled to receive and filter samples from the super-sampled sample buffer to form output pixels and alpha pixels in real time, wherein the alpha pixels are usable to form an alpha key. The graphics system may be further configured to receive a video input signal and overlay the video input signal with the output pixels according to said alpha pixels.
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