Teruo Fumoto

Fast color processor with programmable interpolation by small memory (PRISM)

We present a novel color processor with programmable interpolation by small memory (PRISM). The input/output signals to/from the devices are flexibly converted by a 3-0 look-up table (LUT) with a PRISM interpolator. The PRISM architecture provides a simple computation algorithm with sufficient accuracy. The performance of PRISM interpolation is compared with other conventional methods. In practice, PRISM is less complicated than CUBE and PYRAMID, and more accurate than PYRAMID and TETRAHEDRON. PRISM cuts the memory size of LUT drastically to an orderof iO compared with a full-size LUT method and brings with it a large-scale integration color processor operating at a higher than video rate. The PRISM structure is the most suitable for the perceptual color spaces such as YCrCb or CIELAB and very useful for device-independent color reproduction and transmission. Typical applications by a PRISM color processor are presented.