Wavelet encoding method and apparatus and wavelet decoding method and apparatus
AssigneesSony Corporation, Hitoshi Kiya
InventorsTAKAHIRO FUKUHARA, SEIJI KIMURA, HITOSHI KIYA
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Abstract
A wavelet encoding method and apparatus and a wavelet decoding method and apparatus for pictures. A input picture is split into plural tile pictures and wavelet transform is applied to input pictures on the tile picture basis to effect the encoding. For wavelet transform, pixels lying on the outer side of a given tile picture are symmetrically expanded and convolved. This enables marked memory capacity reduction, while eliminating constraint conditions for the number of times of wavelet splitting.
Claims24
A wavelet encoding apparatus comprising:
- -means for splitting an input picture into a plurality of tile pictures;
- means for applying wavelet transform from one tile picture to another;
- means for scanning wavelet transform coefficients;
- means for quantizing wavelet transform coefficients;
- quantizing as-scanned quantization coefficients;
- and
- means for entropy encoding the quantization coefficients to output an encoded bitstream;
- said wavelet transform means including means for symmetrically expanding pixels in a given tile picture within a range outside said tile picture influenced by filtering and for executing convolution.
A wavelet encoding method comprising the steps of:
- splitting an input picture into a plurality of tile pictures;
- applying wavelet transform to said input picture from one tile picture to another;
- scanning wavelet transform coefficients;
- quantizing as-scanned wavelet transform coefficients;
- and
- entropy encoding the quantization coefficients to output an encoded bitstream;
- said wavelet transform step including a step of symmetrically expanding pixels in a given tile picture to a range outside said tile picture influenced by filtering and of executing convolution.
A wavelet decoding apparatus comprising:
- means for being fed with or reading out an encoded bitstream for entropy decoding said encoded bitstream;
- means for dequantizing produced quantization coefficients;
- means for back-scanning the produced quantization coefficients to restore the original sequence of coefficients;
- means for inverse wavelet transforming back-scanned coefficients to generate tile pictures;
- and
- means for synthesizing produced tile pictures to furnish an ultimate output picture.
A wavelet decoding method comprising the steps of:
- being fed with or reading out an encoded bitstream for entropy decoding said encoded bitstream;
- dequantizing produced quantization coefficients;
- back-scanning the produced quantization coefficients to restore the original sequence of coefficients;
- inverse wavelet transforming back-scanned coefficients to generate tile pictures;
- and
- synthesizing produced tile pictures to furnish an ultimate output picture.
A wavelet encoding/decoding apparatus for splitting an input picture into a plurality of tile pictures, wavelet encoding the input picture from one tile picture to another to generate an encoded bitstream and for wavelet decoding the encoded bitstream;
- said wavelet transform means including means for symmetrically expanding and convolving wavelet transform coefficients in the inside of a given tile picture to a range outside the tile picture affected by filtering, there being no overlapping area between said pre-set tile picture and neighboring tile picture(s);
- inverse wavelet transform means, as counterpart means of said wavelet transform means, including means for symmetrically expanding and convolving the wavelet transform coefficients in the inside of said pre-set tile picture or means for setting the wavelet transform coefficients in a range outside said pre-set tile picture affected by filtering all to 0 and for effecting convolution.
Dependencies are inferred from the claim text.