Methods and apparatus for artifact removal for bit depth scalability

• US 8,369,422 B2
• Filed: 10/14/2008
• Issued: 02/05/2013
• Est. Priority Date: 10/16/2007
• Status: Active Grant

• 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:
  US12/734,206
• Publication Number:
  US 20100220796A1
• Time in Patent Office: 1,575 Days
• Field of Search: None
• US Class Current: 375/240.29
• 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 image data for image blocks which form a picture by having a deblocking filter remove coding artifacts caused by local inverse tone mapping for intra-layer texture prediction for bit depth-scalability. 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 is based on a difference of inverse tone mapping parameters for the block and at least one adjacent block with respect to the block.

Claims

1. An apparatus, comprising:

an encoder for encoding image data for at least one block of a picture, wherein a deblocking filter removes coding artifacts caused by local inverse tone mapping for intra-layer texture prediction for 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.

2. The apparatus of claim 1, wherein a boundary strength of the deblocking filter is adjusted when macroblock-based inverse tone mapping is used for at least one adjacent block with respect to the at least one block.

3. The apparatus of claim 1, wherein a boundary strength of the deblocking filter is adjusted when inverse tone mapping parameters are different for the at least one block and at least one adjacent block with respect to the at least one block.

4. A method, comprising:

encoding image data for at least one block of a picture, wherein said encoding step comprising applying deblocking filtering to remove coding artifacts caused by local inverse tone mapping for intra-layer texture prediction for 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.

5. The method of claim 4, wherein a boundary strength of the deblocking filtering is adjusted when macroblock-based inverse tone mapping is used for at least one adjacent block with respect to the at least one block.

6. The method of claim 4, wherein a boundary strength of the deblocking filtering is adjusted when inverse tone mapping parameters are different for the at least one block and at least one adjacent block with respect to the at least one block.

7. An apparatus, comprising:

a decoder for decoding image data for at least one block of a picture, wherein a deblocking filter removes coding artifacts caused by local inverse tone mapping for intra-layer texture prediction for 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 7, wherein a boundary strength of the deblocking filter is adjusted when macroblock-based inverse tone mapping is used for at least one adjacent block with respect to the at least one block.

9. The apparatus of claim 7, wherein a boundary strength of the deblocking filter is adjusted when inverse tone mapping parameters are different for the at least one block and at least one adjacent block with respect to the at least one block.

10. The apparatus of claim 7, wherein the deblocking filter is applied inside the motion compensation loop or outside the motion compensation loop.

11. A method, comprising:

decoding image data for at least one block of a picture, wherein said decoding step comprises applying deblocking filtering to remove coding artifacts caused by local inverse tone mapping for intra-layer texture prediction for 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 11, wherein a boundary strength of the deblocking filtering is adjusted when macroblock-based inverse tone mapping is used for at least one adjacent block with respect to the at least one block.

13. The method of claim 11, wherein a boundary strength of the deblocking filtering is adjusted when inverse tone mapping parameters are different for the at least one block and at least one adjacent block with respect to the at least one block.

14. The method of claim 11, wherein the deblocking filter is applied inside the motion compensation loop or outside the motion compensation loop.

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

image data encoded for at least one block of a picture, wherein the image data is deblocking filtered to remove coding artifacts caused by local inverse tone mapping for intra-layer texture prediction for 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.