1. An apparatus for adaptive entropy encoding within an image or video encoder, comprising: a computer or an encoder (136) having a processing element and memory, said computer or encoder (136) configured for image/video encoding; said computer or encoder is configured to perform steps comprising, dividing an image or a video frame into blocks, decorrelating each block using a transform, quantizing the transform coefficients, selecting a desired tree structure from multiple candidates in response to determination of geometric relationships within the block of pixels for the image, and encoding the block using clustering of zero coefficients in response to the selected tree structure; wherein a portion of the zero coefficients are eliminated from the encoded output in response to having non-leaf nodes of said selected tree structure represent that respective leaf nodes contain only zero coefficients and not coding these descendent leaf nodes into an encoded output bit stream.

2. The apparatus as claimed in claim 1, wherein said tree structure has leaf and non-leaf nodes in a specified arrangement; and wherein one or more leaf nodes containing coefficients are associated with each non-leaf node.

3. The apparatus as claimed in claim 1, wherein said encoding of the block is performed in response to the selected tree structure according to a predetermined traversal of the tree structure; or wherein the state of each non-leaf node is represented by a bit indicating whether its descendent leaf nodes contain all zero coefficients, or do not contain all zero coefficients; or wherein a set of tree structures are retained in the encoder and configured for allowing one of the tree structures to be selected in response to said selection of tree structure; or wherein said geometric relationships which can be recognized within the blocks are selected from the group of geometric block relationships consisting of flat, noisy, horizontal, vertical, diagonal +45°, diagonal - 45°.

4. The apparatus as claimed in claim 1, wherein said computer or encoder (136) is configured to provide information to a decoder (142) about which transform was used when decorrelating blocks of the image.

5. The apparatus as claimed in claim 1, wherein said computer or encoder (136) is configured to provide information to a decoder about which tree structure was selected for use in coding each block of the image.

6. The apparatus as claimed in claim 1, wherein said computer or encoder (136) is configured to perform steps comprising:29 providing information to a decoder about which tree structure was selected for use in coding each block of the image; and wherein said information comprises communicating at least one index for said selected tree structure to a decoder (142) configured for receiving the encoded image.

7. The apparatus as claimed in claim 1, wherein said geometric relationship comprises a two-dimensional relationship between the coefficients in the current block being coded.

8. The apparatus as claimed in claim 1, wherein said computer or encoder (136) is configured for interblock prediction or pre-filtering of the block prior to transform.

9. The apparatus as claimed in claim 1, wherein said block can be of any desired shape and size, including block sizes selected from the group of block sizes consisting of 4x4, 8x8 and 16x16, 32x32 coefficient blocks.

10. The apparatus as claimed in claim 1, wherein said computer or encoder (136) is configured to perform the adaptive entropy encoding within an image encoder which is configured for non-embedded encoding.

11. The apparatus as claimed in claim 1, wherein said computer or encoder (136) is configured to perform the adaptive entropy encoding within an image encoder which is configured for embedded encoding, in which encoding is performed across any desired number of bit planes and can be stopped at any desired coding rate.

12. The apparatus as claimed in claim 1, wherein said coding is performed to a desired coding rate in response to fitting within a bit-budget for an encoded image stream.

13. The apparatus as claimed in claim 1, wherein said transform comprises a spectral transform; or wherein said transform comprises either a discrete wavelet transform (DWT) or a discrete cosine transform (DCT), or any overlapped transforms.

14. The apparatus as claimed in claim 1, further comprising: a computer or a decoder (142) having a processing element and memory (154), said computer or decoder (142) is configured for image decoding of the encoded output bit stream; said computer or decoder is configured for outputting an image signal in response to performing steps comprising, determining the tree structure selected by said computer or encoder in encoding the block, decoding leaves of the tree structure into coefficients of an output, outputting zero coefficients within the output in response to decoding non-leaf nodes without non-zero branches, performing dequantizing of the output,30 performing an inverse transform of the output, reconstructing the image signal in response to receipt of the output.

15. A method for adaptive entropy encoding within an image encoder, comprising: dividing an image or a video frame into blocks; decorrelating each block using a spectral transform; quantizing the transform coefficients; selecting a tree structure from multiple candidates in response to determination of two-dimensional geometric relationships within the block for the image; and encoding the block while clustering zero coefficients in response to the selected tree structure; wherein a portion of the zero coefficients are eliminated from the encoded output in response to having non-leaf nodes of said selected tree structure represent that their respective leaf nodes contain only zero coefficients.

28
We claim:-
1. An apparatus for adaptive entropy encoding within an image or video encoder, comprising:
a computer or an encoder (136) having a processing element and memory, said computer or encoder (136)
configured for image/video encoding;
said computer or encoder is configured to perform steps comprising,
dividing an image or a video frame into blocks,
decorrelating each block using a transform,
quantizing the transform coefficients,
selecting a desired tree structure from multiple candidates in response to determination of geometric
relationships within the block of pixels for the image, and
encoding the block using clustering of zero coefficients in response to the selected tree structure;
wherein a portion of the zero coefficients are eliminated from the encoded output in response to having
non-leaf nodes of said selected tree structure represent that respective leaf nodes contain only zero
coefficients and not coding these descendent leaf nodes into an encoded output bit stream.
2. The apparatus as claimed in claim 1,
wherein said tree structure has leaf and non-leaf nodes in a specified arrangement;
and
wherein one or more leaf nodes containing coefficients are associated with each non-leaf node.
3. The apparatus as claimed in claim 1,
wherein said encoding of the block is performed in response to the selected tree structure according to a
predetermined traversal of the tree structure; or
wherein the state of each non-leaf node is represented by a bit indicating whether its descendent leaf
nodes contain all zero coefficients, or do not contain all zero coefficients; or
wherein a set of tree structures are retained in the encoder and configured for allowing one of the tree
structures to be selected in response to said selection of tree structure; or
wherein said geometric relationships which can be recognized within the blocks are selected from the
group of geometric block relationships consisting of flat, noisy, horizontal, vertical, diagonal +45°, diagonal -
45°.
4. The apparatus as claimed in claim 1, wherein said computer or encoder (136) is configured to provide
information to a decoder (142) about which transform was used when decorrelating blocks of the image.
5. The apparatus as claimed in claim 1, wherein said computer or encoder (136) is configured to provide
information to a decoder about which tree structure was selected for use in coding each block of the image.
6. The apparatus as claimed in claim 1, wherein said computer or encoder (136) is configured to perform
steps comprising:29
providing information to a decoder about which tree structure was selected for use in coding each block of
the image; and
wherein said information comprises communicating at least one index for said selected tree structure to a
decoder (142) configured for receiving the encoded image.
7. The apparatus as claimed in claim 1, wherein said geometric relationship comprises a two-dimensional
relationship between the coefficients in the current block being coded.
8. The apparatus as claimed in claim 1, wherein said computer or encoder (136) is configured for interblock prediction or pre-filtering of the block prior to transform.
9. The apparatus as claimed in claim 1, wherein said block can be of any desired shape and size, including
block sizes selected from the group of block sizes consisting of 4x4, 8x8 and 16x16, 32x32 coefficient
blocks.
10. The apparatus as claimed in claim 1, wherein said computer or encoder (136) is configured to perform
the adaptive entropy encoding within an image encoder which is configured for non-embedded encoding.
11. The apparatus as claimed in claim 1, wherein said computer or encoder (136) is configured to perform
the adaptive entropy encoding within an image encoder which is configured for embedded encoding, in
which encoding is performed across any desired number of bit planes and can be stopped at any desired
coding rate.
12. The apparatus as claimed in claim 1, wherein said coding is performed to a desired coding rate in
response to fitting within a bit-budget for an encoded image stream.
13. The apparatus as claimed in claim 1,
wherein said transform comprises a spectral transform; or
wherein said transform comprises either a discrete wavelet transform (DWT) or a discrete cosine transform
(DCT), or any overlapped transforms.
14. The apparatus as claimed in claim 1, further comprising:
a computer or a decoder (142) having a processing element and memory (154), said computer or decoder
(142) is configured for image decoding of the encoded output bit stream;
said computer or decoder is configured for outputting an image signal in response to performing steps
comprising,
determining the tree structure selected by said computer or encoder in encoding the block,
decoding leaves of the tree structure into coefficients of an output,
outputting zero coefficients within the output in response to decoding non-leaf nodes without non-zero
branches,
performing dequantizing of the output,30
performing an inverse transform of the output,
reconstructing the image signal in response to receipt of the output.
15. A method for adaptive entropy encoding within an image encoder, comprising:
dividing an image or a video frame into blocks;
decorrelating each block using a spectral transform;
quantizing the transform coefficients;
selecting a tree structure from multiple candidates in response to determination of
two-dimensional geometric relationships within the block for the image; and
encoding the block while clustering zero coefficients in response to the selected tree structure;
wherein a portion of the zero coefficients are eliminated from the encoded output in response to having
non-leaf nodes of said selected tree structure represent that their respective leaf nodes contain only zero
coefficients.