Method and apparatus for implementing motion detection in video compression

• US 20020106019A1
• Filed: 01/12/2001
• Published: 08/08/2002
• Est. Priority Date: 03/14/1997
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Gupta, Anoop, Wang, Albert, Chaddha, Navin
• Granted Patent: US 6,639,945 B2
• Time in Patent Office: Days
• US Class Current: 375/240.02
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 19/184 the unit being bits, e.g. of the compressed video stream
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/91 Entropy coding, e.g. variable length coding [VLC] or arithmetic coding
• CPC Class Codes: H04N 19/94 Vector quantisation

Abstract

The present invention relates, in one aspect, to a method for processing video data that is divided into frames. The video data includes a current frame, which has an associated current macroblock, and an adjacent frame, which also has an associated macroblock. The method for processing video data involves obtaining an uncompressed current block that is a part of the current macroblock and an adjacent block that is part of the adjacent macroblock, and calculating a distance between the uncompressed current block and the adjacent block. It is determined whether the distance between the uncompressed current block and the adjacent block is acceptable. If the distance is unacceptable, then the current block is adaptively compressed.

Claims

1. A computer-implemented method for processing video data, the video data including a current frame and an adjacent frame, the current frame including an uncompressed current block, the adjacent frame including an adjacent block, the method comprising:

obtaining the current block and the adjacent block;

calculating a distance between the current block and the adjacent block;

determining if the distance between the current block and the adjacent block is acceptable; and

adaptively compressing the current block when it is determined that the distance between the current block and the adjacent block is not acceptable.

2. A computer-implemented method as recited in claim 1 further including sending a header for motion detection, the header being arranged to indicate if the current block has been compressed.

3. A computer-implemented method as recited in claim 2 further including obtaining compressed bits using the header, wherein obtaining the compressed bits involves a tree map.

4. A computer-implemented method as recited in claim 3 further including determining if the header for motion detection indicates if the current block has been compressed, wherein if the header for motion detection indicates that the current block has been compressed, the compressed bits are decompressed using an adaptive compression decoder.

5. A computer-implemented method as recited in claim 3 wherein the tree map is a binary tree map.

6. A computer-implemented method as recited in claim 2 wherein obtaining the current block involves segmenting the current frame.

7. A computer-implemented method for performing a colorspace conversion on bits associated with video data, the method comprising:

obtaining bits which identify a codebook index for a component;

using the codebook index to obtain pixel representations for the component;

dithering the pixel representations; and

using the dithered pixel representations to obtain an index for the component.

8. A computer-implemented method for performing a colorspace conversion as recited in claim 7 further including clipping the dithered pixel representations.

9. A computer-implemented method for performing a colorspace conversion as recited in claim 7 further including decoding the dithered pixel representations.

10. A computer-implemented method for performing a colorspace conversion as recited in claim 7 wherein the dithered pixel representations are added to other pixel representations associated with other components, and the added pixel representations are decoded.

11. A computer-implemented image processing system comprising:

an encoder arranged to encode video data using adaptive compression techniques; and

a decoder arranged to accept the encoded video data and to decode the encoded video data, wherein the decoder includes a table-based N-stage Huffman decoder and a colorspace converter.

12. A computer-implemented image processing system according to claim 11 wherein the colorspace converter is a table-based luminance and chrominance space to colorspace converter.

13. A computer-implemented image processing system according to claim 11 further including a network delivery system arranged to channel the encoded video data from the encoder to the decoder.

14. A computer-implemented image processing system according to claim 11 wherein N is greater than one.

16. A computer-readable medium for furnishing downloadable computer-readable program code instructions as recited in claim 15, further including program code instructions configured to cause a computer to execute the additional step of including sending a header for motion detection, the header being arranged to indicate if the current block has been compressed.

17. A computer-readable medium for furnishing downloadable computer-readable program code instructions as recited in claim 16 further including program code instructions configured to cause a computer to execute the additional step of obtaining compressed bits using the header, wherein obtaining the compressed bits involves a tree map.

18. A computer-readable medium for furnishing downloadable computer-readable program code instructions as recited in claim 17 further including program code instructions configured to cause a computer to execute the additional step of determining if the header for motion detection indicates if the current block has been compressed, wherein if the header for motion detection indicates that the current block has been compressed, the compressed bits are decompressed using an adaptive compression decoder.

19. A computer-readable medium for furnishing downloadable computer-readable program code instructions as recited in claim 16 wherein the tree map is a binary tree map.

20. A computer-readable medium for furnishing downloadable computer-readable program code instructions as recited in claim 15 wherein the step of obtaining the current block involves segmenting the current frame.

15. A computer-readable medium for furnishing downloadable computer-readable program code instructions configured to cause a computer to process video data, the video data including a current frame and an adjacent frame, the current frame including an uncompressed current block, the adjacent frame including an adjacent block, the computer-readable medium comprising computer program code instructions configured to cause a computer to execute the steps of:

obtaining the current block and the adjacent block;

calculating a distance between the current block and the adjacent block;

determining if the distance between the current block and the adjacent block is acceptable; and

adaptively compressing the current block when it is determined that the distance between the current block and the adjacent block is not acceptable.

21. A computer-readable medium for furnishing downloadable computer-readable program code instructions configured to cause a computer to perform a colorspace conversion on bits associated with video data, the computer-readable medium comprising computer program code instructions configured to cause a computer to execute the steps of:

obtaining bits which identify a codebook index for a component;

using the codebook index to obtain pixel representations for the component;

dithering the pixel representations; and

using the dithered pixel representations to obtain an index for the component.

22. A computer-readable medium for furnishing downloadable computer-readable program code instructions as recited in claim 21 further including program code instructions configured to cause a computer to execute the additional step of clipping the dithered pixel representations.

23. A computer-readable medium for furnishing downloadable computer-readable program code instructions as recited in claim 21 further including program code instructions configured to cause a computer to execute the additional step of decoding the dithered pixel representations.

24. A computer-readable medium for furnishing downloadable computer-readable program code instructions as recited in claim 21 wherein the dithered pixel representations are added to other pixel representations associated with other components, and the added pixel representations are decoded.