Granted Patent B2

US 12,707,082 · App. 18/895,939 · Granted Aug 11, 2026

Inventors: Heiko Schwarz (Berlin, DE); Heiner Kirchhoffer (Berlin, DE); Philipp Helle (Berlin, DE); Simon Oudin (Berlin, DE); Jan Stegemann (Berlin, DE); Benjamin Bross (Berlin, DE); Detlev Marpe (Berlin, DE); Thomas Wiegand (Berlin, DE)

Assignee: Dolby Video Compression, LLC

H04N19/52H04N19/172H04N19/176H04N19/184H04N19/50H04N19/70

Abstract

Claims (74)

1 . An apparatus for decoding a bitstream into which an image is encoded, the apparatus comprising:

a subdivider configured to subdivide the image into a plurality of sample sets of samples;

a merger configured to merge the plurality of sample sets into a plurality of groups each including one or more sample sets;

a decoder configured to decode the image using coding parameters transmitted in the bitstream in units of the groups of the sample sets, wherein the decoder is configured to decode the image by predicting the image, decoding a prediction residual for a predetermined sample set and combining the prediction residual and a prediction resulting from predicting the image for the predetermined sample set;

an extractor configured to extract the prediction residual and the coding parameters from the bitstream together with one or more syntax elements for each of at least a subset of a respective sample set, the one or more syntax elements indicating whether the respective sample set is to be merged into one of the plurality of groups together with another sample set or not, wherein the merger is configured to perform the merging in response to the one or more syntax elements,

wherein the extractor and the merger are configured to:

sequentially step through the sample sets according to a sample set scan order,

for a current sample set, extract a first binary syntax element from the bitstream using arithmetically decoding using a first context,

if the first binary syntax element is determined to be a first binary state, merge the current sample set into one group of the plurality of groups by inferring that coding parameters for the current sample set are equal to coding parameter associated with the group, skip extraction of the prediction residual for the current sample set, and step to a next sample set according to the sample set scan order,

if the first binary syntax element is determined to be a second binary state, extract a second syntax element from the bitstream using arithmetically decoding using a second context different from the first context, and

depending on the second syntax element,

extract a third syntax element from the bitstream using arithmetically decoding using a third context different from the first context and the second context, merge the current sample set into one of the plurality of groups by inferring that coding parameters indicated by the third syntax element for the current sample set are equal to coding parameters associated with one of a set of predetermined candidate sample sets neighboring the respective sample set, and extract at least one further syntax element related to the prediction residual for the current sample set, or

extract the coding parameters for the current sample set, and extract at least one further syntax element related to the prediction residual for the current sample set,

wherein the prediction residual is represented by a transformation coefficient level.

2 . The apparatus according to claim 1 , wherein:

the extractor is further configured to extract subdivision information from the bitstream, and

the subdivider is configured to subdivide the image into sample sets in response to the subdivision information.

3 . The apparatus according to claim 1 , wherein:

the bitstream further comprises a depth map associated with the image.

4 . An apparatus for encoding an image, the apparatus comprising:

a subdivider configured to subdivide the image into a plurality of sample sets of samples;

a merger configured to merge the plurality of sample sets into a plurality of groups each including one or more sample sets;

an encoder configured to encode the image using coding parameters that vary across the image in units of the groups of the sample sets, wherein the encoder is configured to encode the image by predicting the image and encoding a prediction residual for a predetermined sample set;

a bitstream generator configured to insert the prediction residual and the coding parameters into a bitstream together with one or more syntax elements for each of at least a subset of a respective sample set, the one or more syntax elements indicating whether the respective sample set is to be merged into one of the plurality of groups together with another sample set or not,

wherein the bitstream generator is configured to:

sequentially step through the sample sets according to a sample set scan order,

for a current sample set, insert a first binary syntax element into the bitstream using arithmetically encoding using a first context,

wherein if the first binary syntax element is determined to be a first binary state, the first binary syntax element indicates that the current sample set is merged into one group of the plurality of groups by inferring that coding parameters for the current sample set are equal to coding parameter associated with the group, and indicates skipping extraction of the prediction residual for the current sample set and stepping to a next sample set according to the sample set scan order,

if the first binary syntax element is determined to be a second binary state, insert a second syntax element into the bitstream using arithmetically encoding using a second context different from the first context, and insert at least one further syntax element related to the prediction residual for the current sample set,

wherein the second syntax element indicates whether to merge the current sample set into one of the plurality of groups or whether to perform extraction of the coding parameters for the current sample set,

if the second syntax element indicates to merge the current sample set, insert a third syntax element into the bitstream and merge the current sample set by inferring that coding parameters indicated by the third syntax element for the current sample set are equal to coding parameters associated with one of a set of predetermined candidate sample sets neighboring the respective sample set, using arithmetically encoding using a third context different from the first context and the second context,

wherein the prediction residual is represented by a transformation coefficient level.

5 . The apparatus according to claim 4 , wherein:

the bitstream further comprises a depth map associated with the image.

6 . A method for decoding a bitstream into which an image is encoded, the method comprising:

subdividing the image into a plurality of sample sets of samples;

merging the plurality of sample sets into a plurality of groups each including one or more sample sets;

decoding the image using coding parameters transmitted in the bitstream in units of the groups of the sample sets, by predicting the image, decoding a prediction residual for a predetermined sample set and combining the prediction residual and a prediction resulting from predicting the image for the predetermined sample set;

extracting the prediction residual and the coding parameters from the bitstream together with one or more syntax elements for each of at least a subset of a respective sample set, the one or more syntax elements indicating whether the respective sample set is to be merged into one of the plurality of groups together with another sample set or not, wherein the merging is performed in response to the one or more syntax elements;

sequentially stepping through the sample sets according to a sample set scan order;

for a current sample set, extracting a first binary syntax element from the bitstream using arithmetically decoding using a first context;

if the first binary syntax element is determined to be a first binary state, merging the current sample set into one group of the plurality of groups by inferring that coding parameters for the current sample set are equal to coding parameter associated with the group, skipping extraction of the prediction residual for the current sample set, and stepping to a next sample set according to the sample set scan order;

if the first binary syntax element is determined to be a second binary state, extracting a second syntax element from the bitstream using arithmetically decoding using a second context different from the first context; and

depending on the second syntax element,

extracting a third syntax element from the bitstream using arithmetically decoding using a third context different from the first context and the second context, merging the current sample set into one of the plurality of groups by inferring that coding parameters indicated by the third syntax element for the current sample set are equal to coding parameters associated with one of a set of predetermined candidate sample sets neighboring the respective sample set, and extracting at least one further syntax element related to the prediction residual for the current sample set, or

extracting the coding parameters for the current sample set, and extracting at least one further syntax element related to the prediction residual for the current sample set, wherein the prediction residual is represented by a transformation coefficient level.

7 . The method according to claim 6 , wherein:

the bitstream further comprises a depth map associated with the image.

8 . A method for encoding an image, the method comprising:

subdividing the image into a plurality of sample sets of samples;

merging the plurality of sample sets into a plurality of groups each including one or more sample sets;

encoding the image using coding parameters that vary across the image in units of the groups of the sample sets, by predicting the image and encoding a prediction residual for a predetermined sample set;

inserting the prediction residual and the coding parameters into a bitstream together with one or more syntax elements for each of at least a subset of a respective sample set, the one or more syntax elements indicating whether the respective sample set is to be merged into one of the plurality of groups together with another sample set or not;

sequentially stepping through the sample sets according to a sample set scan order;

for a current sample set, inserting a first binary syntax element into the bitstream using arithmetically encoding using a first context;

wherein if the first binary syntax element is determined to be a first binary state, the first binary syntax element indicates that the current sample set is merged into one group of the plurality of groups by inferring that coding parameters for the current sample set are equal to coding parameter associated with the group, and indicates skipping extraction of the prediction residual for the current sample set and stepping to a next sample set according to the sample set scan order;

if the first binary syntax element is determined to be a second binary state, inserting a second syntax element into the bitstream using arithmetically encoding using a second context different from the first context, and inserting at least one further syntax element related to the prediction residual for the current sample set;

wherein the second syntax element indicates whether to merge the current sample set into one of the plurality of groups or whether to perform extraction of the coding parameters for the current sample set; and

if the second syntax element indicates to merge the current sample set, inserting a third syntax element into the bitstream and merging the current sample set by inferring that coding parameters indicated by the third syntax element for the current sample set are equal to coding parameters associated with one of a set of predetermined candidate sample sets neighboring the respective sample set, using arithmetically encoding using a third context different from the first context and the second context,

wherein the prediction residual is represented by a transformation coefficient level.

9 . The method according to claim 8 , wherein:

the bitstream further comprises a depth map associated with the image.

10 . A method for decoding a bitstream, the method comprising:

receiving and decoding a bitstream, into which an image is encoded by a method according to claim 8 .

11 . The method according to claim 10 , wherein:

the bitstream further comprises a depth map associated with the image.

12 . A method for storing an image, comprising:

storing, on a digital storage medium, a bitstream into which an image is encoded by a method according to claim 9 .

13 . The method according to claim 12 , wherein:

the bitstream further comprises a depth map associated with the image.

14 . A method for transmitting an image, comprising:

transmitting, over a transmission medium, a bitstream into which an image is encoded by a method according to claim 8 .

15 . The method according to claim 14 , wherein:

the bitstream further comprises a depth map associated with the image.

Assignments (3)

Continuity (8)

References Cited (55)