| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an improved method and block transform for image or video encoding and decoding. <P>SOLUTION: In the two-dimensional inverse transformation of de-quantized transform coefficients into output pixel information during decoding, only four additions plus one shift operation are needed, per coefficient, all in sixteen-bit arithmetic. Quantization during encoding and de-quantization (sixteen bits) during decoding, via the use of one of three tables selected based on each coefficient's position, have parameter values that already compensate for factors of other transformation multiplications, except for those of a power of two (e.g. 2 or 1/2), which are performed by a shift operation during the transformation and inverse transformation processes. <P>COPYRIGHT: (C)2003,JPO |
