Apparatus and method for encoding digital image data in a lossless manner

• US 20030021485A1
• Filed: 06/26/2002
• Published: 01/30/2003
• Est. Priority Date: 07/02/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Raveendran, Vijayalakshmi R., Morley, Steven A., Ratzel, John, Thyagarajan, Kadayam
• Granted Patent: US 7,483,581 B2
• Time in Patent Office: Days
• US Class Current: 382/244
• CPC Class Codes: H04N 19/119 Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
• CPC Class Codes: H04N 19/122 Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type
• CPC Class Codes: H04N 19/126 Details of normalisation or weighting functions, e.g. normalisation matrices or variable uniform quantisers
• CPC Class Codes: H04N 19/13 Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC]
• CPC Class Codes: H04N 19/14 Coding unit complexity, e.g. amount of activity or edge presence estimation H04N19/146 takes precedence
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/18 the unit being a set of transform coefficients
• CPC Class Codes: H04N 19/96 Tree coding, e.g. quad-tree coding

Abstract

A method of losslessly compressing and encoding signals representing image information is claimed. A lossy compressed data file and a residual compressed data file are generated. When the lossy compressed data file and the residual compressed data file are combined, a lossless data file that is substantially identical to the original data file is created.

Claims

1. A method of losslessly compressing and encoding signals representing an image, the method comprising:

generating a lossy compressed data file;

generating a residual compressed data file; and

combining the lossy data file with the residual data file to create a lossless data file, wherein the lossless data file is substantially identical to the original data file.

2. The method as set forth in claim 1, wherein the lossy compressed data file and the residual compressed data file are generated on an intraframe basis.

3. The method as set forth in claim 1, wherein the lossy compressed data file and the residual compressed data file are generated on an interframe basis.

4. The method set forth in claim 1, wherein generating utilizes a combination of discrete cosine transform (DCT) and discrete quadtree transform (DQT) techniques.

5. The method set forth in claim 1, wherein generating utilizes Golomb-Rice coding techniques.

6. An apparatus to losslessly compress and encode signals representing an image, the apparatus comprising:

means for generating a lossy compressed data file;

means for generating a residual compressed data file; and

means for combining the lossy data file with the residual data file to create a lossless data file, wherein the lossless data file is substantially identical to the original data file.

7. The apparatus as set forth in claim 6, wherein the means for generating the lossy compressed data file and the means for generating the residual compressed data file are generated on an intraframe basis.

8. The apparatus as set forth in claim 6, wherein the means for generating the lossy compressed data file and the means for generating the residual compressed data file are generated on an interframe basis.

9. The apparatus set forth in claim 6, wherein the means for generating utilizes a combination of discrete cosine transform (DCT) and discrete quadtree transform (DQT) techniques.

10. The method set forth in claim 6, wherein the means for generating utilizes Golomb-Rice coding techniques.

11. A method for losslessly compressing and encoding signals representing an image, the method comprising:

compressing the signals representing the image thereby creating a compressed version of the image;

quantizing the compressed version of the image thereby creating a lossy version of the image;

serializing the quantized compressed version of the image thereby creating a serialized quantized compressed version of the image;

decompressing the compressed version of the image;

determining the differences between the image and the decompressed version of the image thereby creating a residual version of the image; and

outputting the lossy version of the image and the residual version of the image, wherein the combination of the lossy version of the image and the residual version of the image is substantially the same as the original image.

12. The method set forth in claim 11, wherein the lossless compression is on an intraframe basis.

13. The method set forth in claim 11, wherein compressing utilizes a combination of discrete cosine transform (DCT) and discrete quadtree transform (DQT) techniques.

14. The method set forth in claim 11, wherein serializing utilizes Golomb-Rice coding techniques.

15. A method for losslessly compressing and encoding signals representing image information, the image comprising a plurality of frames, the method comprising:

compressing a first frame thereby creating a compressed version of the image;

quantizing the compressed version of the image thereby creating a lossy version of the image;

serializing the quantized compressed version of the image thereby creating a serialized quantized compressed version of the image;

compressing a second frame of signals representing the image;

determining the differences between the first frame and the second frame of the image thereby creating a residual version of the image; and

outputting the lossy version of the image with the residual version of the image, wherein the combination of the lossy version of the image and the residual version of the image is substantially the same as the original image.

16. The method set forth in claim 15, wherein the lossless compression is on an interframe basis.

17. The method set forth in claim 15, wherein compressing utilizes a combination of discrete cosine transform (DCT) and discrete quadtree transform (DQT) techniques.

18. The method set forth in claim 15, wherein serializing utilizes Golomb-Rice coding techniques.

19. An apparatus for losslessly compressing and encoding signals representing an image, the method comprising:

means for compressing the signals representing the image thereby creating a compressed version of the image;

means for quantizing the compressed version of the image thereby creating a lossy version of the image;

means for serializing the quantized compressed version of the image thereby creating a serialized quantized compressed version of the image;

means for decompressing the compressed version of the image;

means for determining the differences between the image and the decompressed version of the image thereby creating a residual version of the image; and

means for outputting the lossy version of the image and the residual version of the image, wherein the combination of the lossy version of the image and the residual version of the image is substantially the same as the original image.

20. The apparatus set forth in claim 19, wherein the lossless compression is on an intraframe basis.

21. The apparatus set forth in claim 19, wherein the means for compressing utilizes a combination of discrete cosine transform (DCT) and discrete quadtree transform (DQT) techniques.

22. An apparatus for losslessly compressing and encoding signals representing image information, the image comprising a plurality of frames, the method comprising:

means for compressing a first frame thereby creating a compressed version of the image;

means for quantizing the compressed version of the image thereby creating a lossy version of the image;

means for serializing the quantized compressed version of the image thereby creating a serialized quantized compressed version of the image;

means for compressing a second frame of signals representing the image;

means for determining the differences between the first frame and the second frame of the image thereby creating a residual version of the image; and

means for outputting the lossy version of the image with the residual version of the image, wherein the combination of the lossy version of the image and the residual version of the image is substantially the same as the original image.

23. The apparatus set forth in claim 22, wherein the lossless compression is on an interframe basis.

24. The apparatus set forth in claim 22, wherein the means for compressing utilizes a combination of discrete cosine transform (DCT) and discrete quadtree transform (DQT) techniques.

25. An apparatus for losslessly compressing and encoding signals representing an image, the method comprising:

a compressor element configured to perform discrete cosine transforms (DCTs) and discrete quadtree transforms (DQTs) to the signals representing the image thereby creating a compressed version of the image;

a quantizer element coupled to the compressor element configured to quantize the compressed version of the image thereby creating a lossy version of the image;

a serializer element coupled to the quantizer element configured to serialize the quantized compressed version of the image thereby creating a serialized quantized compressed version of the image;

a decompressor element configured to perform inverse DCTs (IDCTs) and inverse DQTs (IDQTs) the compressed version of the image;

a determiner element configured to determine the differences between the image and the decompressed version of the image thereby creating a residual version of the image; and

a combiner element configured to combine the lossy version of the image and the residual version of the image, wherein the combination of the lossy version of the image and the residual version of the image is substantially the same as the original image.