Adjusting quantization/scaling and inverse quantization/scaling when switching color spaces
AssigneeMicrosoft Technology Licensing, LLC
InventorsBin Li, Jizheng Xu, Gary J. Sullivan
Life of this patent
Estimating the term…
Abstract
Innovations in adaptive encoding and decoding for units of a video sequence can improve coding efficiency when switching between color spaces during encoding and decoding. For example, some of the innovations relate to adjustment of quantization or scaling when an encoder switches color spaces between units within a video sequence during encoding. Other innovations relate to adjustment of inverse quantization or scaling when a decoder switches color spaces between units within a video sequence during decoding.
Claims20
In a computing device that implements a video encoder, a method comprising:
- encoding units of video to produce encoded data, including, when switching from a first color space to a second color space between two of the units, adjusting final quantization parameter (“QP”) values or intermediate QP values for color components of the second color space according to per component color space adjustment factors, wherein the first color space is RGB and the second color space is YCoCg, and wherein the per component color space adjustment factors adjust the final QP values or intermediate QP values for the color components of the second color space by rule for Y, Co and Cg components, respectively, the per component color space adjustment factors depending on the second color space without signaling of syntax elements that indicate the per component color space adjustment factors;
- and
- outputting the encoded data as part of a bitstream.
One or more computer-readable media storing computer-executable instructions for causing one or more processing units, when programmed thereby, to perform operations comprising:
- encoding units of video to produce encoded data, including, when switching from a first color space to a second color space between two of the units, adjusting final quantization parameter (“QP”) values or intermediate QP values for color components of the second color space according to per component color space adjustment factors, wherein the first color space is RGB and the second color space is YCoCg, and wherein the per component color space adjustment factors adjust the final QP values or intermediate QP values for the color components of the second color space by rule for Y, Co and Cg components, respectively, the per component color space adjustment factors depending on the second color space without signaling of syntax elements that indicate the per component color space adjustment factors;
- and
- outputting the encoded data as part of a bitstream.
A computing device comprising:
- one or more buffers configured to store encoded data as part of a bitstream;
- and
- a video decoder configured to perform operations comprising:
- receiving the encoded data;
- and
- decoding the encoded data to reconstruct units of video, including, when switching to a first color space from a second color space between two of the units, adjusting final quantization parameter (“QP”) values or intermediate QP values for color components of the second color space according to per component color space adjustment factors, wherein the first color space is RGB and the second color space is YCoCg, and wherein the per component color space adjustment factors adjust the final QP values or intermediate QP values for the color components of the second color space by rule for Y, Co and Cg components, respectively, the per component color space adjustment factors depending on the second color space without signaling of syntax elements that indicate the per component color space adjustment factors.
Dependencies are inferred from the claim text.