US 11,843,775 B2
Flexible quantization
Chengjie Tu, Sammamish, WA (US); and Sridhar Srinivasan, Redmond, WA (US)
Assigned to Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed by Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed on Apr. 25, 2022, as Appl. No. 17/728,070.
Application 17/728,070 is a continuation of application No. 17/188,977, filed on Mar. 1, 2021, granted, now 11,343,503.
Application 17/188,977 is a continuation of application No. 16/825,239, filed on Mar. 20, 2020, granted, now 10,958,907, issued on Mar. 23, 2021.
Application 16/825,239 is a continuation of application No. 15/973,264, filed on May 7, 2018, granted, now 10,602,146, issued on Mar. 24, 2020.
Application 15/973,264 is a continuation of application No. 14/263,584, filed on Apr. 28, 2014, granted, now 9,967,561, issued on May 8, 2018.
Application 14/263,584 is a continuation of application No. 11/418,690, filed on May 5, 2006, granted, now 8,711,925, issued on Apr. 29, 2014.
Prior Publication US 2022/0256154 A1, Aug. 11, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/124 (2014.01); H04N 19/176 (2014.01); H04N 19/46 (2014.01); H04N 19/61 (2014.01); H04N 19/126 (2014.01); H04N 19/136 (2014.01)
CPC H04N 19/124 (2014.11) [H04N 19/126 (2014.11); H04N 19/136 (2014.11); H04N 19/176 (2014.11); H04N 19/46 (2014.11); H04N 19/61 (2014.11)] 20 Claims
OG exemplary drawing
 
1. A computer system comprising one or more processing units and memory, wherein the computer system implements a video decoder configured to perform operations comprising:
receiving encoded data in a bitstream, wherein the encoded data includes:
one or more syntax elements that control variation of quantization parameters along a spatial dimension within a frame of pixel values, the pixel values of the frame being organized spatially into multiple areas within the frame, the multiple areas being further organized spatially into groups, the one or more syntax elements that control variation of the quantization parameters along the spatial dimension including at least one syntax element that indicates whether variation of the quantization parameters is possible between the multiple areas within the respective groups;
one or more syntax elements that control variation of the quantization parameters along a color channel dimension, the pixel values of the frame also being organized by first, second, and third color channels, the one or more syntax elements that control variation of the quantization parameters along the color channel dimension including a syntax element that indicates whether, for a given group of the groups, the encoded data includes syntax elements that indicate how to vary the quantization parameters for the second and third color channels, respectively, for the given group; and
for the given group, the syntax elements that indicate how to vary the quantization parameters for the second and third color channels, respectively, for the given group; and
decoding the encoded data to reconstruct the frame, wherein the decoding includes:
determining the quantization parameters using the one or more syntax elements that control variation of the quantization parameters along the spatial dimension, the one or more syntax elements that control variation of the quantization parameters along the color channel dimension, and the syntax elements that indicate how to vary the quantization parameters for the second and third color channels, respectively, for the given group;
for blocks of at least some of the multiple areas of the frame, inverse quantizing transform coefficients using the determined quantization parameters; and
for the blocks of at least some of the multiple areas of the frame, performing inverse frequency transform operations on the inverse-quantized transform coefficients.