ENHANCED ANTI-ALIASING BY VARYING SAMPLE PATTERNS SPATIALLY AND/OR TEMPORALLY

• US 20160071242A1
• Filed: 09/05/2015
• Published: 03/10/2016
• Est. Priority Date: 09/10/2014
• Status: Active Grant

• Current Assignee: NVIDIA Corporation
• Original Assignee: NVIDIA Corporation
• Inventors: URALSKY, Yury Y., ALBEN, Jonah M., LUM, Eric B., BANJEREE, Ankan, MASSAL, Gregory, PETERSON, Thomas, KUZNETSOV, Oleg, MEHTA, Prakshep
• Granted Patent: US 10,096,086 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06T 1/20 Processor architectures; Processor configuration, e.g. pipelining
• CPC Class Codes: G06T 11/001 Texturing; Colouring; Generation of texture or colour inpainting G06T5/77
• CPC Class Codes: G06T 2200/12 involving antialiasing
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/20182 Noise reduction or smoothing in the temporal domain; Spatio-temporal filtering
• CPC Class Codes: G06T 5/00 Image enhancement or restoration
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/70 Denoising; Smoothing

Abstract

A raster unit is configured to generate different sample patterns for adjacent pixels within a given frame. In addition, the raster unit may adjust the sample patterns between frames. The raster unit includes an index unit that selects a sample pattern table for use with a current frame. For a given pixel, the index unit extracts a sample pattern from the selected sample pattern table. The extracted sample pattern is used to generate coverage information for the pixel. The coverage information for all pixels is then used to generate an image. The resultant image may then be filtered to reduce or remove artifacts induced by the changing of sample locations.

Claims

1. A graphics subsystem, comprising:

a first sample pattern table that includes a first plurality of entries; and

an index unit configured to;

generate a first index into the first sample pattern table that references a first subset of entries included in the first plurality of entries, and

extract the first subset of entries from the first sample pattern table, wherein a first entry included in the first subset of entries indicates a first location within a first pixel of a first frame where a first sample is to be generated.

2. The graphics subsystem of claim 1, wherein the index unit is further configured to determine a frame number associated with the first frame and to select the first sample pattern table from a plurality of sample pattern tables based on the frame number.

3. The graphics subsystem of claim 1, wherein the index unit is further configured to receive a set of coordinates associated with the first pixel and to generate the first index based on at least a portion of the set of coordinates.

4. The graphics subsystem of claim 3, wherein the set of coordinates comprises an X coordinate and a Y coordinate, and the index unit is further configured to:

parse one or more least significant bits from the X coordinate;

parse one or more least significant bits from the Y coordinate; and

combine the one or more least significant bits from the X coordinate with the one or more least significant bits from the Y coordinate to generate the first index.

5. The graphics subsystem of claim 1, wherein the index unit is further configured to:

generate a second index into the first sample pattern table that references a second subset of entries included in the first plurality of entries; and

extract the second subset of entries from the first sample pattern table, wherein a second entry included in the second subset of entries indicates a second location within a second pixel of the first frame where a second sample is to be generated.

6. The graphics subsystem of claim 1, further comprising a second sample pattern table that includes a second plurality of entries, wherein the index unit is further configured to:

generate a second index into the second sample pattern table that references a second subset of entries included in the second plurality of entries; and

extract the second subset of entries from the second sample pattern table, wherein a second entry included in the second subset of entries indicates a second location within a second pixel of a second frame where a second sample is to be generated.

7. The graphics subsystem of claim 6, wherein the first pixel resides at a first set of X-Y coordinates within the first frame, and the second pixel resides at the first set of X-Y coordinates within the second frame.

8. The graphics subsystem of claim 6, wherein the index unit is further configured to:

generate a third index into the second sample pattern table, wherein the third index refers to a third subset of entries in the second plurality of entries; and

extract the third subset of entries from the second sample pattern table, wherein a third entry included in the third subset of entries indicates a third location within a third pixel of the second frame where a third sample is to be generated.

9. The graphics subsystem of claim 8, wherein the second pixel resides at a second set of X-Y coordinates within the second frame, and the third pixel resides at the first set of X-Y coordinates within the second frame.

10. The graphics subsystem of claim 1, wherein the first sample comprises a coverage sample, and wherein a shader unit coupled to the graphics subsystem is configured to generate a shader sample at the first location for the first pixel and to process the shader sample to generate a color value for the first pixel.

11. A computer-implemented method for generating samples of pixel, the method comprising:

generating a first index into a first sample pattern table that includes a first plurality of entries, wherein the first index references a first subset of entries included in the first plurality of entries, and

extracting the first subset of entries from the first sample pattern table, wherein a first entry included in the first subset of entries indicates a first location within a first pixel of a first frame where a first sample is to be generated.

12. The computer-implemented method of claim 11, further comprising:

determining a frame number associated with the first frame; and

selecting the first sample pattern table from a plurality of sample pattern tables based on the frame number.

13. The computer-implemented method of claim 11, further comprising:

receiving a set of coordinates associated with the first pixel; and

generating the first index based on at least a portion of the set of coordinates.

14. The computer-implemented method of claim 13, wherein the set of coordinates comprises an X coordinate and a Y coordinate, further comprising:

parsing one or more least significant bits from the X coordinate;

parsing one or more least significant bits from the Y coordinate; and

combining the one or more least significant bits from the X coordinate with the one or more least significant bits from the Y coordinate to generate the first index.

15. The computer-implemented method of claim 11, further comprising:

generating a second index into the first sample pattern table that references a second subset of entries included in the first plurality of entries; and

extracting the second subset of entries from the first sample pattern table, wherein a second entry included in the second subset of entries indicates a second location within a second pixel of the first frame where a second sample is to be generated.

16. The computer-implemented method of claim 11, further comprising:

generating a second index into a second sample pattern table that includes a second plurality of entries, wherein the second index references a second subset of entries included in the second plurality of entries; and

extracting the second subset of entries from the second sample pattern table, wherein a second entry included in the second subset of entries indicates a second location within a second pixel of a second frame where a second sample is to be generated.

17. The computer-implemented method of claim 16, wherein the first pixel resides at a first set of X-Y coordinates within the first frame, and the second pixel resides at the first set of X-Y coordinates within the second frame.

18. The computer-implemented method of claim 11, further comprising receiving, from a software application, the plurality of sample pattern tables.

19. The computer-implemented method of claim 18, wherein the software application includes a number of sample pattern tables in the plurality of sample pattern tables that reflects a first multiframe antialiasing mode.

20. A computing device, comprising:

a graphics subsystem, including;

a first sample pattern table that includes a first plurality of entries; and

an index unit configured to;

generate a first index into the first sample pattern table that references a first subset of entries included in the first plurality of entries, and

extract the first subset of entries from the first sample pattern table, wherein a first entry included in the first subset of entries indicates a first location within a first pixel of a first frame where a first coverage sample is to be generated.

21. The computing device of claim 20, further comprising:

a shader unit coupled to the graphics subsystem and configured to;

generate a first shader sample for the first pixel at the first location, and

generate a first color value for the first pixel based on the first shader sample.

22. The computing device of claim 21, wherein the first pixel resides at a first set of X-Y coordinates within the first frame, and a second pixel resides at the first set of X-Y coordinates within a second frame, and wherein the shader unit is further configured to:

generate a second shader sample for the second pixel at the second location, and

generate a second color value for the second pixel based on the second shader sample.