| 摘要 |
A method and apparatus for implementing a new imaging and image composition system based on the real world metaphor of surface absorption, reflection, and transmission where many layers of translucent and opaque objects are composed into a final image for output to a video display. The algorithms are a substitution for both "Painter's algorithm" (the image composition technique traditionally used in computer graphic systems) and the alpha blending algorithms presently used in the computer and television industries for video special effects such as cross-fades between images, transparency, and color keying. In contrast to the prior art "colored pixel" algorithms, this system is based on a light propagation metaphor that uses virtual light source illumination and the absorption, reflection, and transmission properties of the objects in the image to create the final screen image. Thus, instead of representing each picture element (pixel) by color components specified by a chosen color model (e.g., RGB, YUV, Lab, HSV, YIQ, HLS, CMY, CMYK, etc.), the pixels in the subject system are represented by six explicit transformation components (r1, r2, r3, t1, t2, t3) and three implicit transformation components (a1, a2, a3), wherein a, r and t refer to absorption, reflection and transmission, respectively, and the subscripts 1, 2 and 3 refer to the components of the chosen color model.
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