System and method for graphics compression

• US 10,462,465 B2
• Filed: 01/02/2015
• Issued: 10/29/2019
• Est. Priority Date: 01/02/2015
• Status: Active Grant

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Schoner, Brian Francis, Pande, Anand, Vadakkumthodam Radhakrishnan, Praveen
• Primary Examiner(s): Crawford, Jacinta M
• Application Number:
  US14/588,615
• Publication Number:
  US 20160196632A1
• Time in Patent Office: 1,761 Days
• Field of Search: 345505, 345555, 345501
• CPC Class Codes: G06T 9/00 Image coding bandwidth or redundancy reduction for static pictures H04N1/41; coding or decoding of static colour picture signals H04N1/64; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00
• CPC Class Codes: H04N 19/136 Incoming video signal characteristics or properties
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/463 by compressing encoding parameters before transmission
• CPC Class Codes: H04N 19/593 involving spatial prediction techniques

Abstract

A system and method for processing graphics are provided. Pixel data may be received for a pixel block. Endpoints for the values of the pixels in the pixel block may be determined. A weight for the pixels in the pixel block may be determined in four dimensions corresponding to the endpoints. A compressed data block representative of the pixel block may be generated in response to the endpoints for the pixel block and the weight for the pixels of the pixel block in the four dimensions corresponding to the endpoints.

Claims

1. A graphics processor comprising:

endpoint selection circuitry operable to;

receive pixel data for a pixel block;

determine first endpoints for first values of pixels in the pixel block and a first error for the first endpoints, the first endpoints corresponding to a first component of a multi-component plane comprising a first number of components;

determine second endpoints for second values of the pixels in the pixel block and a second error for the second endpoints, the second endpoints corresponding to a second component of another multi-component plane comprising no more than a second number of components, the second number of components being less than the first number of components; and

select one of the first endpoints or the second endpoints as selected endpoints based at least in part on a comparison of the first error to the second error; and

packing circuitry operable to;

receive the selected endpoints for the pixel block and a weight for each pixel of the pixel block corresponding to the selected endpoints; and

generate a compressed data block representative of the pixel block.

2. The graphics processor according to claim 1, wherein one of the components of the multi-component plane comprises an independent alpha component.

3. The graphics processor according to claim 2, wherein the multi-component plane comprises a red component, a green component, and a blue component.

4. The graphics processor according to claim 1, wherein the pixel block is a non-square pixel block and the pixel block includes a greater number of pixels along a raster direction than a non-raster direction.

5. The graphics processor according to claim 4, wherein the pixel block includes a width of a single pixel along the non-raster direction.

6. The graphics processor according to claim 5, wherein the pixel block includes a width of eight pixels along a raster direction and a width of two pixels along a non-raster direction.

7. The graphics processor according to claim 5, wherein the pixel block includes a width of sixteen pixels along a raster direction and a width of one pixel along a non-raster direction.

8. The graphics processor of claim 1, further comprising:

weight selection circuitry operable to receive the pixel data for the pixel block, the weight selection circuitry operable to determine the weight for each pixel of the pixel block in each plane corresponding to the selected endpoints for the block.

9. A method for processing graphics comprising:

receiving, in a graphics processor, pixel data for a pixel block;

determining, in the graphics processor, a first error for determined first endpoints for values of the pixels in the pixel block, the determined first endpoints corresponding to a first component of a multi-component plane comprising a first number of components;

determining, in the graphics processor, a second error for determined second endpoints for second values of the pixels in the pixel block, the determined second endpoints corresponding to a second component of another multi-component plane comprising no more than a second number of components that is less than the first number of components;

selecting one of the first or second endpoints as selected endpoints based at least in part on a comparison of the first error to the second error; and

generating, in the graphics processor, a compressed data block representative of the pixel block in response to the selected endpoints for the pixel block and a weight for each pixel of the pixel block corresponding to the selected endpoints.

10. The method according to claim 9, further comprising:

determining, in the graphics processor, a weight for each pixel of the pixel block in each plane corresponding to the selected endpoints for the pixel block.

11. The method according to claim 10, wherein the determining the first error occurs substantially in parallel with the determining the second error.

12. The method according to claim 10, further comprising:

determining, in the graphics processor, the first and second endpoints.

13. The method according to claim 10, wherein the determining the weight for each pixel of the pixel block includes a division.

14. The method according to claim 13, wherein a dividend of the division comprises a value of the pixel and a divisor of the division comprises a range of the selected endpoints.

15. The method according to claim 14, wherein a remainder of the division is used as an estimate of an error for the weighting.

16. The method according to claim 9, wherein selecting one of the first or second endpoints further comprises:

determining whether values of the pixels in the pixel block exceed a value threshold;

determining whether a number of pixels, that exceed the value threshold, exceed a pixel count threshold; and

setting the endpoints to a default value in response to the number of pixels exceeding the pixel count threshold.

17. The method according to claim 16, wherein the default value for the endpoints include a maximum range value and a minimum range value.

18. The method according to claim 16, wherein selecting endpoints further comprises:

expanding a number of bits allocated to the weight for each pixel of the pixel block in response to setting the endpoints to the default value.

19. A method for processing graphics comprising:

receiving, in a graphics processor, pixel data for a pixel block;

determining, in the graphics processor, first endpoints for first component values of the pixels in the pixel block, the endpoints corresponding to a first component of a multi-component plane comprising a first number of components;

determining a first error for the first endpoints;

determining, in the graphics processor, second endpoints for second component values of the pixels in the pixel block, the second endpoints corresponding to a second component of another multi-component plane comprising no more than three components;

determining a second error for the second endpoints;

comparing the first error for the first endpoints corresponding to the first component of the multi-component plane comprising four components to the second error for the second endpoints corresponding to the second component of the other multi-component plane comprising no more than a second number of components that is less than the first number of components;

selecting one of the first endpoints or the second endpoints as selected endpoints in response to the comparing of the first error to the second error; and

generating, in the graphics processor, a compressed data block representative of the pixel block in response to the selected endpoints for the pixel block and a weight for each pixel of the pixel block corresponding to the selected endpoints.

20. The method according to claim 19, wherein a division operation is performed for each pixel of the pixel block, a dividend of the division operation comprises a value of the pixel and a divisor of the division operation comprises a range of the selected endpoints, a remainder of the division operation is used as an estimate of the error for weighting each pixel.