Telefonaktiebolaget Lm Ericsson (publ)

Jack Enhorn

Kenneth Andersson

Zhi Zhang

Jacob Ström

Rickard Sjöberg

Martin Pettersson

Mitra Damghanian

Ruoyang Yu

Per Wennersten

Du Liu

Jonatan Samuelsson

Thomas Rusert

Ying Wang

Julien Michot

Lukasz Litwic

A method () for processing an image. The method includes obtaining (s) a set of sample values associated with the image, the set of sample values comprising a current sample value and sample values neighboring the current sample value, wherein the obtained set of sample values is included within a rectangular block of sample values, and the current sample value has a vertical position, y. The method also includes selecting (s) a filter strength value based on y, wherein selecting the filter strength value based on y comprises: selecting a first filter strength value if a condition is satisfied, otherwise if the condition is not satisfied selecting a second filter strength value, wherein the condition is satisfied only when y is equal to a predetermined value and the condition is not satisfied if y is not equal to the predetermined value. The method also includes filtering (s) the current sample based on the selected filter strength value.

Adaptive loop filter (ALF) virtual boundry processing

A method for deblocking at least one boundary of a coding unit, wherein the boundary forms a first side and a second side of the coding unit, wherein a video picture comprises the coding unit, and wherein the first and second sides use a same reference picture. The method includes obtaining a first motion vector component in the first side; obtaining a second motion vector component in the second side; determining whether an absolute difference between the first motion vector component and the second motion vector component is equal to or larger than a predetermined threshold that is less than 1 sample; and as a result of determining that the absolute difference between the first motion vector component and the second motion vector component is equal to or larger than the predetermined threshold, applying deblocking to the vertical or horizontal boundary between the first side and the second side.

Deblocking using sub-PEL motion vector threshold

A method for deblocking is provided. The method includes checking whether a size of a current block exceeds a size threshold. The method includes checking whether a size of an adjacent block exceeds the size threshold. The adjacent block is adjacent to a boundary of the current block. The method includes determining that a criteria is true. The criteria comprises both a size of the current block and a size of the adjacent block exceeding the size threshold. The method includes, as a result of determining that the criteria is true, applying a long-tap deblocking across the boundary of the current block. A length of the long-tap deblocking is greater than 7.

Extra-long tap deblocking

The long filter decision in VVC is modified by adding at least one gradient check that at least includes sample p6 or q6. This makes it possible to avoid using the long filters when there is some natural structure at sample p6 or q6. In one specific embodiment at least two gradient checks including both q6 and p6 are added. In another embodiment, the dpq threshold is modified from beta>>2 to beta>>4. This threshold change embodiment may be used in conjunction with or instead of the embodiment in which a gradient check that includes p6 and/or q6 is added to the long filter decision.

Deblocking filter selection in video or image coding

There is provided a method for processing a bitstream. The method comprises determining a value, N, wherein N identifies a number of ordered layer representations, wherein N is greater than or equal to 3 such that the N ordered layer representations comprises a highest layer representation, a second highest layer representation, and a third highest layer representation. The method further comprises determining a value for the highest layer representation. The method comprises, after determining the value for the highest layer representation and before determining a value for the third highest layer representation, determining a value for the second highest layer representation. The method comprises, after determining the value for the second highest layer representation, determining a value for the third highest layer representation.

Derivation of a value for each layer representation of a bitstream

A method for making a smooth prediction block of samples in a picture in an image or video encoder or decoder is provided. The method includes determining parameters r of a polynomial model by r=(BB)*(B*x), where B is a matrix of bases and x is a source of samples in vector form. The method includes predicting a block x' based on the parameters r and the matrix of bases B.

Smooth surface prediction

A method for decoding a picture comprising a virtual boundary from a coded video bitstream. The method includes determining one or more of a maximum picture width or a maximum picture height from one or more syntax elements S1 in the coded video bitstream and determining one or more of a current picture width or a current picture height from one or more syntax elements S2 in the coded video bitstream. The method also includes determining that a virtual boundary syntax element in the coded video bitstream is encoded with a bit length derived from (i) one or more of the maximum picture width or the maximum picture height or (ii) one or more of the current picture width or the current picture height. The method also includes deriving the bit length for the virtual boundary syntax element based on (i) the one or more of the maximum picture width or maximum picture height as a result of determining that a virtual boundary syntax element in the coded video bitstream is encoded with a bit length derived from one or more of the maximum picture width or the maximum picture height or (ii) the one or more of the current picture width or the current picture height as a result of determining that a virtual boundary syntax element in the coded video bitstream is derived from one or more of the current picture width or the current picture height. The method also includes decoding the virtual boundary syntax element from the bitstream based on the derived bit length and determining a spatial picture position of the virtual boundary based on the decoded virtual boundary syntax element.

Virtual boundary signaling

A methods and apparatuses for encoding or decoding a segment in a coded picture. The decoding may include obtaining from a bitstream a value of a first codeword that indicates whether the coded picture may contain bi-directional inter coded segments or not. The decoding may include, based on the value of the first codeword, deriving one or more parameter values by either (a) decoding one or more parameters from the bitstream to obtain the one or more parameter values or (b) inferring the one or more parameter values. The decoding may include decoding the segment in the coded picture based on the one or more parameter values. The encoding may include encoding the first codeword to the bitstream and determining whether to encode one or more parameter values in the bitstream based on a determination of whether the coded picture will contain bi-directional inter coded segments or not.

Decoding based on bi-directional picture condition

A method and decoder for determining that a decoder conforming to a first profile is capable of decoding a first picture of a video bitstream conforming to a second profile is provided. The method includes obtaining an indicator value, the indicator value indicating conformance to a profile. The method includes determining whether the first picture in the video bitstream is a still picture. The method includes responsive to the indicator value indicating conformance to the second profile and the first picture is determined to be a still picture, determining that the decoder conforming to the first profile is capable of decoding the first picture of the video bitstream.

Determining capability to decode a first picture in a video bitstream

Methods, decoders, and programs are provided. All blocks of an image that has been encoded are decoded. At least one sample of at least one block of the image is filtered by, for each block being filtered: for each sample being filtered: selecting a plurality of neighboring samples. For at least one neighboring sample, a difference is calculated between the neighboring sample and the sample. A modifier value is obtained. A modifier sum is derived based on a sum of the modifier values for the neighboring samples. A correction value is determined based on a conditional addition of at least one shifted version of the modifier sum, each shift having a same number of shift steps in each correction value determination. A filtered sample is derived based on the sample and correction value. The filtered sample is stored. The block and filtered sample is output towards a decoder output.

Bilateral loop filter

A method for deblocking at least one boundary of a coding unit. The method includes determining that the coding unit uses a sub-block transform, wherein the sub-block transform generates a transform sub-block boundary within the coding unit, thereby forming at least a transform sub-block within the coding unit; as a result of determining that the coding unit uses the sub-block transform, determining a maximum filter length based on a dimension of the transform sub-block within the coding unit, wherein the maximum filter length indicates a maximum number of samples to modify when deblocking a boundary of the coding unit; and deblocking the boundary of the coding unit based on the determined maximum filter length.

Deblocking of transform sub-block boundaries

A method for deriving a value for a first syntax element, Syntax_A. The method comprises determining whether Syntax_A is present in a bitstream. The method comprises, as a result of determining that Syntax_A is not present in the bitstream, deriving the value for Syntax_A to be equal to a first value, B, if a first condition is satisfied, or deriving the value for Syntax_A to be equal to a second value, C, if a second condition is satisfied.

Video processing

A deblocking method for deblocking a boundary between a first block of samples, block P, and a second block of samples, block Q. The method includes determining whether at least one of the P block or the Q block is a combined intra-inter prediction block; and, as a result of determining that at least one of the P block or the Q block is a combined intra-inter prediction block, deblocking the boundary between the P block and the Q block.

Deblocking in a video encoder and/or video decoder

An encoder, a decoder, and methods for partitioning a picture from a sequence of video pictures into a layout having a plurality of flexible tiles or segments is disclosed. Each tile or segment comprises a single rectangular or square region. The encoder generates a partition structure and encodes the tiles according to the partition structure. The encoder also generates a bitstream comprising a plurality of coded segments and information indicating the partition structure used to partition the picture into the plurality of flexible tiles or segments, and sends the bitstream to the decoder. Upon receipt, the decoder uses the coded segments and information in the bitstream to decode the plurality of coded segments.

Tile partitions with sub-tiles in video coding

A method for encoding or decoding an image. The method includes obtaining a coding tree block (CTB) having a vertical size (CtbSizeY) and a horizontal size (CtbSizex), the CTB comprising set of sample values associated with the image, the set of sample values comprising a current sample value having a location (x,y) within the CTB, where x is a horizontal value and y is a vertical value. The method also includes selecting a filter strength value for the current sample based on y and filtering the current sample using the selected filter strength value. Selecting a filter strength value for the current sample based on y comprises: i) determining whether the following first condition is true: (y==(CtbSizeY−5) OR y==(CtbSizeY−4)) AND var==1, where var is a variable that is set equal to 1 as a result of a determination that a second condition is satisfied; and ii) choosing a filter strength value of 10 as a result of determining that the first condition is true.

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Jack Enhorn