System and method providing improved data compression via wavelet coefficient encoding

• US 7,065,252 B1
• Filed: 03/28/2005
• Issued: 06/20/2006
• Est. Priority Date: 01/08/2001
• Status: Expired due to Term

• Current Assignee: OL Security LLC (Intellectual Ventures LLC)
• Original Assignee: Microsoft Corporation
• Inventors: Malvar, Henrique S, Simard, Patrice Y
• Primary Examiner(s): Grant, II, Jerome
• Application Number:
  US11/091,068
• Time in Patent Office: 449 Days
• Field of Search: 382/232, 382/166, 382/207, 382/206, 382/236, 382/245, 382/251, 382/253, 382/250, 358/426.01, 358/426.13, 358/426.14, 358/426.02
• US Class Current: 382/232
• CPC Class Codes: H04N 19/129 Scanning of coding units, e.g. zig-zag scan of transform coefficients or flexible macroblock ordering [FMO]
• CPC Class Codes: H04N 19/1883 the unit relating to sub-band structure, e.g. hierarchical level, directional tree, e.g. low-high [LH], high-low [HL], high-high [HH]
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets

Abstract

A data compression system is provided in accordance with the present invention. The system includes a scanning component which scans at least a portion of a transformed image. The scan is performed substantially in a horizontal direction on a first section of the portion and in a vertical direction on a second section of the portion to enable improved data compression of the transformed image. The horizontal and vertical scan directions are performed via a contiguous scan of the respective sections to further enable improved data compression of the transformed image.

Claims

1. A data compression system, comprising:

a scanning component which scans at least a portion of a transformed image, wherein the scan is performed substantially in a horizontal direction on a first section of the portion and in a vertical direction on a second section of the portion to enable improved data compression of the transformed image; and

a quantizer that reduces stored data associated with wavelet coefficients that correspond to the transformed image.

2. The data compression system of claim 1, wherein the horizontal and vertical scan directions are performed via a contiguous scan of the respective sections to enable improved data compression of the transformed image.

3. The data compression system of claim 1, further comprising a wavelet transform subsystem for transforming image into wavelet coefficients via low pass and high pass filters applied to the image.

4. The data compression system of claim 3, further comprising a reordering and blocking subsystem to provide a matrix of wavelet coefficients that are organized into at least one of low—

low (LL), low-high (LH), high-low (HL), and high—

high (HH) sub-bands.

5. The data compression system of claim 4, wherein the LH sub-bands are scanned in the vertical direction and the HL sub-bands are scanned in the horizontal direction.

6. The data compression system of claim 4, wherein the LL and HH sub-bands are scanned in either the horizontal or the vertical direction.

7. The data compression system of claim 4, wherein run length encoding is employed to encode the scanned coefficients.

8. The data compression system of claim 7, wherein at least one of Golomb-Rice encoding and Arithmetic encoding is employed to encode the scanned coefficients.

9. A method for providing a data compression system, comprising:

scanning at least a portion of a transformed image in substantially a horizontal direction on a first section of the portion;

scanning in a vertical direction on a second section of the portion of the transformed image to enable improved data compression of the transformed image; and

reducing data associated with wavelet coefficients that correspond to the transformed image.

10. The method of claim 9, further comprising:

transforming an image into wavelet coefficients via low pass and high pass filters applied to the image.

11. The method of claim 10, further comprising:

reordering and blocking to provide a matrix of wavelet coefficients that are organized into at least one of low—

low (LL), low-high (LH), high-low (HL), and high—

high (HH) sub-bands.

12. The method of claim 11, wherein the LH sub-bands are scanned in the vertical direction and the HL sub-bands are scanned in the horizontal direction.

13. The method of claim 11, wherein the LL and HH sub-bands are scanned in either the horizontal or the vertical direction.

14. The method of claim 9, wherein the horizontal and vertical scan directions are performed via a contiguous scan of the respective sections to enable improved data compression of the transformed image.

15. A data compression system, comprising:

means for scanning at least a portion of a transformed image in substantially a horizontal direction on a first section of the portion;

means for scanning in a vertical direction on a second section of the portion of the transformed image to enable improved data compression of the transformed image; and

means for reducing data associated with wavelet coefficients that correspond to the transformed image.

16. The data compression system of claim 15, further comprising:

means for transforming an image into wavelet coefficients via low pass and high pass filters applied to the image.

17. The data compression system of claim 16, further comprising:

means for reordering and blocking to provide a matrix of wavelet coefficients that are organized into at least one of low—

low (LL), low-high (LH), high-low (HL), and high—

high (HH) sub-bands.

18. The data compression system of claim 17, wherein the LH sub-bands are scanned in the vertical direction and the HL sub-bands are scanned in the horizontal direction.

19. The data compression system of claim 15, wherein the horizontal and vertical scan directions are performed via a contiguous scan of the respective sections to enable improved data compression of the transformed image.