公开(公告)号：US11861869B2

公开(公告)日：2024-01-02

申请号：US18069466

申请日：2022-12-21

申请人： BlackBerry Limited

发明人： Sébastien Lasserre ,  David Flynn

IPC分类号： G06T9/40 ,  G06T3/40 ,  G06T9/00

CPC分类号： G06T9/40 ,  G06T3/40 ,  G06T9/001

摘要： Methods and devices for encoding a point cloud. A bit sequence signaling an occupancy pattern for sub-volumes of a volume is coded using binary entropy coding. Contexts may be based on neighbour configuration and a partial sequence of previously-coded bits of the bit sequence. A determination is made as to whether to apply a context reduction operation and, if so, the operation reduces the number of available contexts. Example context reduction operations include reducing neighbour configurations based on shielding by sub-volumes associated with previously-coded bits, special handling for empty neighbour configurations, and statistics-based context consolidation.

公开(公告)号：US10964068B2

公开(公告)日：2021-03-30

申请号：US16356098

申请日：2019-03-18

申请人： BlackBerry Limited ,  2236008 Ontario Inc.

发明人： David Flynn ,  Sébastien Lasserre

IPC分类号： G06T9/20 ,  G06T3/40 ,  G06T9/40

摘要： Methods and devices for attribute coding for point clouds. In a top-down coding process a predicted geometry-weighted sum of attributes is determined for each occupied sub-volume of a volume based on a prediction operation that uses at least a geometry-weighted sum of attributes for the volume. The prediction operation involves up-sampling data from the preceding (parent) depth of the coding tree. The predicted geometry-weighted sums of attributes and corresponding original geometry-weighted sums of attributes are subtracted, in the attribute domain or in a transform domain to result in residual coefficients. The AC residual coefficients are coded in the bitstream. The transform used has a DC coefficient property, whereby the DC coefficient from transform of the geometry-weighted sums of attributes for the set of child sub-volumes is the geometry-weighted sum of attributes for the volume.

公开(公告)号：US10587286B1

公开(公告)日：2020-03-10

申请号：US16356087

申请日：2019-03-18

申请人： BlackBerry Limited ,  2236008 Ontario Inc.

发明人： David Flynn ,  Sébastien Lasserre

IPC分类号： H03M7/40

摘要： Methods of encoding and decoding data in which some data symbols are entropy coded and some data symbols are bypass coded. The encoder separates the coded symbols into an entropy coded stream and a bypass coded stream. The streams are packaged in a data unit that has a payload structured to contain one of the streams in forward order and the other stream in reverse order, with the reverse order stream aligned with the end of the data unit. In this manner, at the decoder, the decoder may begin decoding the forward order stream from its beginning and may also begin decoding the reverse order stream from its beginning at the end of the data unit by extracting symbols in reverse order. The data unit does not need to signal the length of the streams. The decoder determines the length of the data unit from explicit or implicit signaling.

公开(公告)号：US11258458B2

公开(公告)日：2022-02-22

申请号：US17258839

申请日：2019-07-08

申请人： BlackBerry Limited

发明人： Sébastien Lasserre ,  David Flynn

IPC分类号： H03M7/30 ,  H03M7/40

摘要： Methods and devices for lossy encoding of point clouds. Rate-distortion optimization is used in coding an occupancy pattern for a sub-volume to determine whether to invert any of the bits of the occupancy pattern. The assessment may be a greedy evaluation of whether to invert bits in the coding order. Inverting a bit of the occupancy pattern amounts to adding or removing a point from the point cloud. A distortion metric may measure distance between the point added or removed and its nearest neighbouring point.

公开(公告)号：US09264724B2

公开(公告)日：2016-02-16

申请号：US14051968

申请日：2013-10-11

申请人： BLACKBERRY LIMITED

发明人： Jing Wang ,  Dake He ,  David Flynn

IPC分类号： H04N19/13 ,  H04N19/159 ,  H04N19/176

CPC分类号： H04N19/13 ,  H04N19/159 ,  H04N19/176 ,  H04N19/18 ,  H04N19/60 ,  H04N19/625 ,  H04N19/70

摘要： Methods of encoding and decoding sign information for non-zero coefficients in a block of video with transform skipped. The methods include context-based coding of a flag that signals if all signs are the same in the block; using a finite state machine to determine contexts for coding of sign information, some of which may be context-based coded and some of which may be non-context-based coded; context-based coding of sign information wherein the context is based upon the signs of neighbouring coefficients; context-based coding of sign information, where the sign information is a prediction of the sign; and using a dedicated context to code signs with a sign flag indicating whether signs in a transform skipping block have been inverted to preserve a dominant sign bias.

公开(公告)号：US11455749B2

公开(公告)日：2022-09-27

申请号：US16955513

申请日：2019-01-10

申请人： BlackBerry Limited

发明人： David Flynn ,  Sébastien Lasserre

IPC分类号： G06T9/40 ,  G06F17/18 ,  H03M7/30 ,  H04N19/105 ,  H04N19/13 ,  H04N19/169 ,  H04N19/46 ,  H04N19/96 ,  G06T9/00 ,  G06T17/10

摘要： Methods and devices for encoding a point cloud. A current node associated with a sub-volume is split into further sub-volumes, each further sub-volume corresponding to a child node of the current node, and, at the encoder, an occupancy pattern is determined for the current node based on occupancy status of the child nodes. A probability distribution is selected from among a plurality of probability distributions based on occupancy data for a plurality of nodes neighbouring the current node. The encoder entropy encodes the occupancy pattern based on the selected probability distribution to produce encoded data for the bitstream and updates the selected probability distribution. The decoder makes the same selection based on occupancy data for neighbouring nodes and entropy decodes the bitstream to reconstruct the occupancy pattern.

公开(公告)号：US11356116B2

公开(公告)日：2022-06-07

申请号：US17267823

申请日：2019-09-09

申请人： BlackBerry Limited

发明人： Sébastien Lasserre ,  David Flynn

IPC分类号： H03M7/30

摘要： Methods and systems for encoding and decoding data, such as point cloud data. The methods may include using a coder map to map a range of discrete dependency states to a smaller set of binary coders each having an associated coding probability. The selection of one of the discrete dependency states may be based on a contextual or situational factors, which may include a prediction process, for a particular symbol, such as an occupancy bit. The coder map is updated after each symbol is coded to possibly alter to which binary coder the selected discrete dependency state maps.

公开(公告)号：US11089331B2

公开(公告)日：2021-08-10

申请号：US17045815

申请日：2019-04-03

申请人： BlackBerry Limited

发明人： Sébastien Lasserre ,  David Flynn

IPC分类号： H04N19/597 ,  H04N19/13 ,  H04N19/00 ,  H04N19/159 ,  H04N19/50 ,  H04N19/152 ,  H04N19/52

摘要： Methods and devices for encoding a point cloud. A bit sequence signaling an occupancy pattern for sub-volumes of a volume is coded. Predictive coding is used to find a set of predicted points, from which a corresponding predicted occupancy pattern may be determined. The predicted occupancy pattern may be used to determine the contexts for entropy coding the occupancy pattern. The determination may include determining for each sub-volume, whether it contains a predicted point or not and, in some cases, the count of predicted points within the sub-volume. Various threshold numbers of predicted points may cause the selection of different context sets for coding the occupancy pattern. The predictive coding may be enabled by determining that the prediction of occupancy of a parent volume to the volume met a threshold level of accuracy.

公开(公告)号：US11051024B1

公开(公告)日：2021-06-29

申请号：US17045782

申请日：2019-04-03

申请人： BlackBerry Limited

发明人： Sébastien Lasserre ,  David Flynn

IPC分类号： H04N19/147 ,  H04N19/91 ,  H04N19/567 ,  H04N19/517 ,  H04N19/105

摘要： Methods and devices for encoding a point cloud. A bit sequence signaling an occupancy pattern for sub-volumes of a volume is coded. Predictive coding is used to find a set of predicted points, from which a corresponding predicted occupancy pattern may be determined. The search for and selection of a coding mode for generating the set of predicted points may include a geometric distortion metric for evaluating how closely the geometry of the predicted set of points aligns with the geometry of the set of points to be coded. The geometric distortion metric may include a sum of absolute value distance between each point and its nearest predicted point. The metric may sum a logarithm of the distances to match more closely with coding rate cost.

公开(公告)号：US09674538B2

公开(公告)日：2017-06-06

申请号：US13858852

申请日：2013-04-08

申请人： BlackBerry Limited

发明人： David Flynn

IPC分类号： H04N19/30 ,  H04N19/61 ,  H04N19/124

CPC分类号： H04N19/30 ,  H04N19/124 ,  H04N19/61

摘要： Methods are provided for reconstructing d-bit samples from coefficients, in an encoded video bit-stream, that had been encoded based on source samples having a bit-depth D, where D>d. A residual process, including inverse-quantization and inverse-transformation processes, is applied to the coefficients to compute (D+1)-bit residual samples. Then a prediction process, including (i) rounding and/or truncating intermediate samples and (ii) subsequently clipping intermediate samples, is applied to the residual samples to compute d-bit reconstructed samples.