Enhanced anti-aliasing by varying sample patterns spatially and/or temporally

Patent metadata

Field	Value
Publication number	US-10147203-B2
Application number	US-201514846738-A
Country	US
Kind code	B2
Filing date	Sep 5, 2015
Priority date	Sep 10, 2014
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

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.

First claim

What is claimed is:

1. A non-transitory computer-readable medium including instructions that, when executed by a processor, cause the processor to filter images, by performing the steps of:
rendering a first image frame and a second image frame, wherein at least one artifact appears between the second image frame and the first image frame;
detecting an amount of motion associated with a first pixel that resides within the first image frame;
based on the amount of motion detected, selecting between:
a first filtering operation to be performed based on the first pixel and at least one other pixel within the second image frame, or
a second filtering operation to be performed based on the first pixel and at least one other pixel in the first image frame; and

reducing the appearance of the at least one artifact by performing the selected filtering operation on the first pixel and at least one other pixel.

2. The non-transitory computer-readable medium of claim 1 , wherein selecting between the first filtering operation and the second filtering operation comprises:
determining that the amount of motion does not exceed a threshold level, and selecting the first filtering operation; or
determining that the amount of motion exceeds the threshold level, and selecting the second filtering operation.

3. The non-transitory computer-readable medium of claim 1 , wherein detecting the amount of motion associated with the first pixel comprises:
comparing a first value associated with the first pixel to a second value associated with a second pixel, wherein the second pixel resides within the second image frame; and
determining a difference between the first value and the second value.

4. The non-transitory computer-readable medium of claim 3 , wherein the first pixel resides at a first position within the first image frame, and the second pixel resides at the first position within the second image frame.

5. The non-transitory computer-readable medium of claim 4 , wherein coverage samples for both the first pixel and the second pixel are generated based on a first sample pattern.

6. The non-transitory computer-readable medium of claim 4 , wherein at least one frame is rendered between the first frame and the second frame, the at least one frame includes at least one pixel for which coverage samples are generated based on a second sample pattern, and the at least one pixel resides at the first position within the at least one frame.

7. The non-transitory computer-readable medium of claim 1 , wherein the first filtering operation comprises a temporal blend operation, and performing the temporal blend operation comprises:
identifying a previous pixel that resides within a previous frame rendered before the first frame; and
blending the first pixel with the previous pixel,
wherein the first pixel resides at a first position within the first frame, and the previous pixel resides at the first position within the previous frame.

8. The non-transitory computer-readable medium of claim 1 , wherein the second filtering operation comprises a spatial blend operation, and performing the spatial blend operation comprises:
identifying an edge within the first frame along which the first pixel and one or more other pixels reside; and
blending the first pixel with the one or more other pixels.

9. The non-transitory computer-readable medium of claim 1 , further comprising the steps of:
determining a sample shift direction associated with the first pixel;
identifying a neighboring pixel that resides within the first frame opposite to the sample shift direction relative to the first pixel; and
blending the first pixel with the neighboring pixel to generate a first color value for the first pixel.

10. The non-transitory computer-readable medium of claim 9 , further comprising the steps of:
identifying a previous pixel that resides within a previous frame rendered before the first frame; and
blending the first pixel with the previous pixel to generate a second color value for the first pixel.

11. The non-transitory computer-readable medium of claim 10 , further comprising the steps of:
determining that the amount of motion exceeds a threshold value;
increasing a motion score associated with the first pixel; and
combining the first color value with the second color value based on the motion score to generate a color value for the first pixel.

12. The non-transitory computer-readable medium of claim 10 , further comprising the steps of:
determining that the amount of motion does not exceed a threshold value;
decreasing a motion score associated with the first pixel; and
combining the first color value with the second color value based on the motion score to generate a color value for the first pixel.

13. The non-transitory computer-readable medium of claim 1 , further comprising the steps of:
determining that the amount of motion exceeds a threshold value;
increasing a motion score associated with the first pixel;
determining a sample shift direction associated with the first pixel;
identifying a neighboring pixel that resides within the first frame opposite to the sample shift direction relative to the first pixel; and
blending the first pixel with the neighboring pixel to generate a color value for the first pixel.

14. The non-transitory computer-readable medium of claim 1 , further comprising the steps of:
determining that the amount of motion does not exceed a threshold value;
decreasing a motion score associated with the first pixel;
identifying a previous pixel that resides within a previous frame rendered before the first frame;
computing a reversed motion score based on the motion score; and
blending the first pixel with the previous pixel based on the reversed motion score to generate a color value for the first pixel.

15. The non-transitory computer-readable medium of claim 14 , wherein computing the reversed motion score comprises subtracting the motion score from an integer value.

16. A computer-implemented method for filtering images, comprising:
rendering a first image frame and a second image frame, wherein at least one artifact appears between the second image frame and the first image frame;
detecting an amount of motion associated with a first pixel that resides within the first image frame;
based on the amount of motion detected, selecting between:
a first filtering operation to be performed based on the first pixel and at least one other pixel within the second image frame, or
a second filtering operation to be performed based on the first pixel and at least one other pixel in the first image frame; and

reducing the appearance of the at least one artifact by performing the selected filtering operation on the first pixel and at least one other pixel.

17. The computer-implemented method of claim 16 , wherein selecting between the first filtering operation and the second filtering operation comprises:
determining that the amount of motion does not exceed a threshold level, and selecting the first filtering operation; or
determining that the amount of motion exceeds the threshold level, and selecting the second filtering operation.

18. The computer-implemented method of claim 16 , wherein detecting the amount of motion associated with the first pixel comprises:
comparing a first value associated with the first pixel to a second value associated with a second pixel, wherein the first pixel resides at a first position within the first image frame, and the second pixel resides at the first position within the se

Assignees

• Nvidia Corp

Inventors

• Uralsky Yury Y
• Alben Jonah M
• Banerjee Ankan
• Massal Gregory
• Petersen Thomas
• Kuznetsov Oleg
• Lum Eric B
• Mehta Prakshep

Classifications

• G06T11/10 Primary

  Texturing; Colouring; Generation of textures or colours (retouching, inpainting or scratch removal G06T5/77) · CPC title

• G06T2200/12

  involving antialiasing · CPC title

• G06T11/001 Primary

  Physics · mapped topic

• G06T11/40 Primary

  Filling planar surfaces by adding surface attributes, e.g. adding colours or textures · CPC title