Moving image encoding device and moving image decoding device based on adaptive switching among transformation block sizes
An encoding controlling unit 3 selects one transformation block size which provides an optimal degree of encoding efficiency from a set of transformation block sizes which are determined in accordance with an encoding mode 7 , and includes the transformation block size selected thereby in optimal compression parameters 20 a to notify the transformation block size to a transformation/quantization unit 19 , and the transformation/quantization unit 19 divides an optimal prediction differential signal 13 a into blocks having the transformation block size included in the optimal compression parameters 20 a , and carries out a transformation and quantization process on each of the blocks to generate compressed data 21.
1. A moving image decoding device which decodes a bit stream generated by dividing an image of a moving image into a plurality of blocks and by compression-encoding the blocks and obtains the moving image, the moving image decoding device comprising:
a motion-compensated predictor to generate an inter prediction images of one of the blocks on a basis of a prediction parameter indicating a reference image for inter prediction processing on the block; and
a variable-length decoder to entropy-decode the bit stream in order to obtain a binary string and obtain the prediction parameter from the binary string,
wherein the variable-length decoder obtains an identifier from the bit stream, the identifier specifying a table from a plurality of binarization tables each of which defines a binary string assignment to the prediction parameter, and obtains the prediction parameter by inverse binarizing the binary string in accordance with the specified binarization table.
2. A moving image decoding method for decoding a bit stream generated by dividing an image of a moving image into a plurality of blocks and by compression-encoding the blocks and obtains the moving image, the moving image decoding method comprising:
obtaining a binary string by entropy-decoding the bit stream;
obtaining a prediction parameter by inverse binarizing the binary string in accordance with a binarization table which is specified from a plurality of binarization tables each of which defines a binary string assignment to the prediction parameter, the identifier being obtained from the bit stream; and
generating an inter prediction images of one of the blocks on a basis of the prediction parameter, the prediction parameter indicating a reference image for inter prediction processing on the block.
3. A moving image encoding device which generates a bit stream by dividing an image of a moving image into a plurality of blocks and by compression-encoding the blocks, the moving image encoding device comprising:
a motion-compensated predictor to generate an inter prediction images of one of the blocks on a basis of a prediction parameter indicating a reference image for inter prediction processing on the block; and
a variable-length encoder to binarize the prediction parameter to a binary string and entropy-encode the binary string into the bit stream,
wherein the variable-length encoder carries out the binarization according to a binarization table specified with an identifier from a plurality of binarization tables, each of which defines a binary string assignment to the prediction parameter, and encodes the identifier into the bit stream.
4. A moving image encoding method of generating a bit stream by dividing an image of a moving image into a plurality of blocks and by compression-encoding the blocks, the moving image encoding method comprising:
generating an inter prediction image of one of the blocks on a basis of a prediction parameter indicating a reference image for inter prediction processing on the block;
binarizing the prediction parameter to a binary string in accordance with a binarization table which is specified with an identifier from a plurality of binarization tables each of which defines a binary string assignment to the prediction parameter, the identifier being encoded into the bit stream; and
entropy-encoding the binary string into the bit stream.
5. A non-transitory computer-readable medium storing a bit stream which is generated by dividing an image of a moving image into a plurality of blocks and by compression-encoding the blocks, the bit stream comprising;
a prediction difference generated by subtracting a prediction image of one of the blocks from the block, the prediction image being generated on a basis of a prediction parameter indicating a reference image for inter prediction processing on the block;
an identifier specifying one of a plurality of binarization tables each of which defines a binary string assignment to the prediction parameter; and
a binary string encoded with entropy-coding, the binary string being obtained by binarizing the prediction parameter in accordance with the binarization table specified by the identifier.