US 10,567,807 B1Granted

Adjustable per-symbol entropy coding probability updating for image and video coding

AssigneeGoogle Inc.

InventorsYaowu Xu, Hui Su

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Abstract

Decoding encoded image data using adjustable per-symbol entropy coding probability updating may include identifying a probability update indicator indicating whether per-symbol entropy coding probability updating is enabled, identifying current entropy coding probabilities, identifying a current entropy coded representation of a current symbol, generating the current symbol by entropy decoding the current entropy coded representation of the current symbol based on the current entropy coding probabilities, in response to a determination that the probability update indicator indicates that per-symbol entropy coding probability updating is enabled for the current portion, generating updated entropy coding probabilities based on the current symbol and the current entropy coding probabilities, generating a decoded current portion using the current symbol, including the decoded current portion in the decoded image data, and outputting the decoded image data.

Claims20

Dependent claims

A method comprising:

generating, by a processor, an encoded video stream by encoding an input video stream using adjustable per-symbol entropy coding probability updating, wherein encoding the input video stream using adjustable per-symbol entropy coding probability updating includes:
identifying a current portion of the input video stream;
including a probability update indicator in an output bitstream, the probability update indicator indicating whether per-symbol entropy coding probability updating is enabled for the current portion;
identifying current entropy coding probabilities for encoding the current portion;
identifying a current symbol from the current portion;
generating an entropy coded representation of the current symbol based on the current entropy coding probabilities;
in response to generating the entropy coded representation of the current symbol:
in response to a determination that the probability update indicator indicates that per-symbol entropy coding probability updating is enabled for the current portion:
generating updated entropy coding probabilities based on the current symbol and the current entropy coding probabilities;
and
identifying the updated entropy coding probabilities as the current entropy coding probabilities;
in response to a determination that the probability update indicator indicates that per-symbol entropy coding probability updating is disabled for the current portion, omitting generating updated entropy coding probabilities;
and
including the entropy coded representation in the output bitstream;
and
outputting the output bitstream.

13 more elements

A method comprising:

generating, by a processor, decoded image data by decoding encoded image data using adjustable per-symbol entropy coding probability updating, wherein decoding the encoded image data using adjustable per-symbol entropy coding probability updating includes:
identifying a current portion of the decoded video stream;
identifying a probability update indicator for the current portion, the probability update indicator indicating whether per-symbol entropy coding probability updating is enabled for the current portion;
identifying current entropy coding probabilities for decoding the current portion;
identifying a current entropy coded representation of a current symbol from the current portion;
generating the current symbol by entropy decoding the current entropy coded representation of the current symbol based on the current entropy coding probabilities;
in response to generating the current symbol:
in response to a determination that the probability update indicator indicates that per-symbol entropy coding probability updating is enabled for the current portion:
generating updated entropy coding probabilities based on the current symbol and the current entropy coding probabilities;
and
identifying the updated entropy coding probabilities as the current entropy coding probabilities;
in response to a determination that the probability update indicator indicates that per-symbol entropy coding probability updating is disabled for the current portion, omitting generating updated entropy coding probabilities;
generating a decoded current portion using the current symbol;
and
including the decoded current portion in the decoded image data;
and
outputting the decoded image data.

14 more elements

An apparatus comprising:

a processor configured to generate decoded image data by decoding encoded image data using adjustable per-symbol entropy coding probability updating, wherein decoding the encoded image data using adjustable per-symbol entropy coding probability updating includes:
identifying a current portion of the decoded video stream;
identifying a probability update indicator for the current portion, the probability update indicator indicating whether per-symbol entropy coding probability updating is enabled for the current portion;
identifying current entropy coding probabilities for decoding the current portion;
identifying a current entropy coded representation of a current symbol from the current portion;
generating the current symbol by entropy decoding the current entropy coded representation of the current symbol based on the current entropy coding probabilities;
in response to generating the current symbol:
in response to a determination that the probability update indicator indicates that per-symbol entropy coding probability updating is enabled for the current portion:
generating updated entropy coding probabilities based on the current symbol and the current entropy coding probabilities;
and
identifying the updated entropy coding probabilities as the current entropy coding probabilities;
in response to a determination that the probability update indicator indicates that per-symbol entropy coding probability updating is disabled for the current portion, omitting generating updated entropy coding probabilities;
generating a decoded current portion using the current symbol;
and
including the decoded current portion in the decoded image data;
and
outputting the decoded image data.

14 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/266,486Filed 4 Feb 2019
Granted: 18 Feb 2020
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H04N 19/91
Using coding techniques not provided for in groups H04N19/10-H04N19/85, e.g. fractals: entropy coding, e.g. variable length coding [VLC] or…
G06F 17/18
Complex mathematical operations: for evaluating statistical data , e.g. average values, frequency distributions, probability functions, regression…
H04N 19/172
The unit being an image region, e.g. an object: the region being a picture, frame or field
H04N 19/176
The unit being an image region, e.g. an object: the region being a block, e.g. a macroblock