Video encoding method and apparatus, and video decoding apparatus
AssigneeFujitsu Limited
InventorsAkihiro YAMORI, Kiyoshi Sakai
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Abstract
To allow a finer quantization control according to the property of an image within a macroblock, quantization parameter values are allowed to be changed in units of sub-blocks equal to or smaller than the macroblock in a similar manner as in motion compensation and orthogonal transform processes. A finer-tuned quantization control is performed, for example, by selecting fine and coarse quantization parameters respectively for corresponding sub-blocks if a plurality of images having different properties coexist within the macroblock.
Claims18
A video encoding method for dividing each frame of a video into macroblocks of a predetermined size, and for encoding each of the macroblocks by combining temporal compression using difference data and motion compensation, an orthogonal transform for transforming spatial information into frequency information, and quantization of an orthogonal transform coefficient, comprising:
- further dividing the macroblocks into small blocks;
- deciding a quantization parameter for each of the small blocks;
- and
- quantizing the orthogonal transform coefficient with the quantization parameter for each of the small blocks.
A video encoding apparatus, which has an orthogonal transform unit for compressing information of image data in a spatial direction and a quantization unit for quantizing an orthogonal transform coefficient of the image data that is orthogonal-transformed by the orthogonal transform unit, for generating video encoding information by dividing each frame of a video into macroblocks of a predetermined size and by encoding the macroblocks, wherein
- the quantization unit divides the macroblocks into small blocks based on quantization division information for dividing the macroblocks into the small blocks, each of which is quantized, and quantizes the orthogonal transform coefficient for each of the small blocks.
Dependencies are inferred from the claim text.