Methods and apparatus for artifact removal for bit depth scalability

• US 8,391,353 B2
• Filed: 10/14/2008
• Issued: 03/05/2013
• Est. Priority Date: 10/16/2007
• Status: Expired due to Fees

• Current Assignee: InterDigital Madison Patent Holdings (InterDigital, Inc.)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Yin, Peng, Luo, Jiancong, Gao, Yong Ying, Wu, Yu Wen
• Primary Examiner(s): Kelley, Christopher S
• Assistant Examiner(s): Tarko, Asmamaw G
• Application Number:
  US12/734,205
• Publication Number:
  US 20100220795A1
• Time in Patent Office: 1,603 Days
• Field of Search: 345/600, 375/240.29, 375/E07.193, 382/232, 382/261, 382/268, 382/275
• US Class Current: 375/240
• CPC Class Codes: H04N 19/134 characterised by the element, parameter or criterion affecting or controlling the adaptive coding
• CPC Class Codes: H04N 19/159 Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/184 the unit being bits, e.g. of the compressed video stream
• CPC Class Codes: H04N 19/30 using hierarchical techniques, e.g. scalability H04N19/63 takes precedence
• CPC Class Codes: H04N 19/36 Scalability techniques involving formatting the layers as a function of picture distortion after decoding, e.g. signal-to-noise [SNR] scalability
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/80 Details of filtering operations specially adapted for video compression, e.g. for pixel interpolation H04N19/635, H04N19/86 take precedence
• CPC Class Codes: H04N 19/82 involving filtering within a prediction loop
• CPC Class Codes: H04N 19/86 involving reduction of coding artifacts, e.g. of blockiness

Abstract

Apparatus and methods are described for encoding and decoding an enhancement layer. A deblocking filter is applied at the enhancement layer for bit depth scalability. The deblocking filter is adjusted to remove coding artifacts caused by local inverse tone mapping for intra-layer texture prediction for the bit depth scalability. The boundary strength of the deblocking filter is adjusted based on a threshold that, in turn, is based on a difference of inverse tone mapping parameters for a block and an adjacent block.

Claims

1. An apparatus, comprising:

an encoder for encoding an enhancement layer for at least a portion of a picture, wherein a deblocking filter is applied at the enhancement layer for bit depth scalability,

wherein the deblocking filter is adjusted to remove coding artifacts caused by local inverse tone mapping for intra-layer texture prediction for the bit depth scalability,

wherein the local inverse tone mapping is block-based, and

wherein a boundary strength of the deblocking filter is adjusted based on a threshold that, in turn, is based on a difference of inverse tone mapping parameters for the at least one block and at least one adjacent block with respect to the at least one block.

6. The apparatus of claim 1, wherein said encoder also encodes a base layer for the at least a portion of the picture, and the deblocking filter is applied jointly at both the base layer and the enhancement layer.

2. A method, comprising:

encoding an enhancement layer for at least a portion of a picture, wherein said encoding step comprising applying deblocking filtering at the enhancement layer for bit depth scalability,

wherein the deblocking filtering is adjusted to remove coding artifacts caused by local inverse tone mapping for intra-layer texture prediction for the bit depth scalability,

wherein the local inverse tone mapping is block-based, and

wherein a boundary strength of the deblocking filtering is adjusted based on a threshold that, in turn, is based on a difference of inverse tone mapping parameters for the at least one block and at least one adjacent block with respect to the at least one block.

7. The method of claim 2, wherein said encoding step comprises encoding a base layer for the at least a portion of the picture, and the deblocking filter is applied jointly at both the base layer and the enhancement layer.

3. An apparatus, comprising:

a decoder for decoding an enhancement layer for at least a portion of a picture, wherein a deblocking filter is applied at the enhancement layer for bit depth scalability,

wherein the deblocking filter is adjusted to remove coding artifacts caused by local inverse tone mapping for intra-layer texture prediction for the bit depth scalability,

wherein the local inverse tone mapping is block-based, and

wherein a boundary strength of the deblocking filter is adjusted based on a threshold that, in turn, is based on a difference of inverse tone mapping parameters for the at least one block and at least one adjacent block with respect to the at least one block.

8. The apparatus of claim 3, wherein said decoder also decodes a base layer for the at least a portion of the picture, and the deblocking filter is applied jointly at both the base layer and the enhancement layer.

9. The apparatus of claim 3, wherein said decoder includes a motion compensation loop.

10. The apparatus of claim 9, wherein the deblocking filter is applied inside the motion compensation loop.

11. The apparatus of claim 9, wherein the deblocking filter is applied outside the motion compensation loop.

4. A method, comprising:

decoding an enhancement layer for at least a portion of a picture, wherein said decoding step comprises applying deblocking filtering at the enhancement layer for bit depth scalability,

wherein the deblocking filtering is adjusted to remove coding artifacts caused by local inverse tone mapping for intra-layer texture prediction for the bit depth scalability,

wherein the local inverse tone mapping is block-based, and

wherein a boundary strength of the deblocking filtering is adjusted based on a threshold that, in turn, is based on a difference of inverse tone mapping parameters for the at least one block and at least one adjacent block with respect to the at least one block.

12. The method of claim 4, wherein said decoding step comprises decoding a base layer for the at least a portion of the picture, and the deblocking filtering is applied jointly at both the enhancement layer and the base layer.

13. The apparatus of claim 4, wherein the deblocking filtering is applied inside a motion compensation loop.

14. The apparatus of claim 4, wherein the deblocking filtering is applied outside a motion compensation loop.

5. A non-transitory computer-readable storage media having video signal data encoded thereupon, comprising:

an enhancement layer encoded for at least a portion of a picture, wherein the enhancement layer is deblocking filtered for bit depth scalability,

wherein the deblocking filtering is adjusted to remove coding artifacts caused by local inverse tone mapping for intra-layer texture prediction for the bit depth scalability,

wherein the local inverse tone mapping is block-based, and

wherein a boundary strength of the deblocking filtering is adjusted based on a threshold that, in turn, is based on a difference of inverse tone mapping parameters for the at least one block and at least one adjacent block with respect to the at least one block.