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公开(公告)号:US12267496B2
公开(公告)日:2025-04-01
申请号:US18358111
申请日:2023-07-25
Applicant: Apple Inc.
Inventor: Hilmi Enes Egilmez , Yunfei Zheng , Alican Nalci , Yeqing Wu , Yixin Du , Guoxin Jin , Alexandros Tourapis , Jun Xin , Hsi-Jung Wu
IPC: H04N7/12 , H04N19/12 , H04N19/122 , H04N19/136 , H04N19/159 , H04N19/176 , H04N19/18 , H04N19/186 , H04N19/61 , H04N19/70
Abstract: Video coders and decoders perform transform coding and decoding on blocks of video content according to an adaptively selected transform type. The transform types are organized into a hierarchy of transform sets where each transform set includes a respective number of transforms and each higher-level transform set includes the transforms of each lower-level transform set within the hierarchy. The video coders and video decoders may exchange signaling that establishes a transform set context from which a transform set that was selected for coding given block(s) may be identified. The video coders and video decoders may exchange signaling that establishes a transform decoding context from which a transform that was selected from the identified transform set to be used for decoding the transform unit. The block(s) may be coded and decoded by the selected transform.
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公开(公告)号:US12192454B2
公开(公告)日:2025-01-07
申请号:US17741259
申请日:2022-05-10
Applicant: Apple Inc.
Inventor: Alexandros Tourapis
IPC: H04N19/117 , H04N19/136 , H04N19/186 , H04N19/44 , H04N19/463 , H04N19/70 , H04N19/82 , H04N19/86
Abstract: Offset values, such as Sample Adaptive Offset (SAO) values in video coding standards such as the High Efficiency Video Coding standard (HEVC), may be improved by performing calculations and operations that improve the preciseness of these values without materially affecting the signal overhead needed to transmit the more precise values. Such calculations and operations may include applying a quantization factor to a video sample and at least some of its neighbors, comparing the quantized values, and classifying the video sample as a minimum, maximum, or one of various types of edges based on the comparison. Other sample range, offset mode, and/or offset precision parameters may be calculated and transmitted with metadata to improve the precision of offset values.
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公开(公告)号:US12170783B2
公开(公告)日:2024-12-17
申请号:US18168390
申请日:2023-02-13
Applicant: APPLE INC.
Inventor: Alexandros Tourapis , Athanasios Leontaris
IPC: H04N19/176 , H04N19/117 , H04N19/14 , H04N19/46 , H04N19/86
Abstract: Video coding schemes may include one or more filters to reduce coding artifacts and improve video quality. These filters may be applied to decode video data in a predetermined sequence. The output from one or more of these filters may be selected for different images, blocks, or sets of video data and then copied and/or routed to a display or a buffer storing reference data that is used to decode other video data in a data stream. Providing the ability to select which filter output is used for display and as a reference may result in better video quality for multiple types of video data. The filters that are selected for display and for reference may be different and may vary for different images, blocks, and data sets.
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公开(公告)号:US20240404112A1
公开(公告)日:2024-12-05
申请号:US18677779
申请日:2024-05-29
Applicant: Apple Inc.
Inventor: Khaled Mammou , Alexandros Tourapis , Jay Mayur Khandhar , Kristian D. Pereira , Borna Ghavam
IPC: G06T9/00
Abstract: Various implementations disclosed herein include devices, systems, and methods that enable compression of two-dimensional (2D) map-based video content. For example, a process may obtain (2D) data sets corresponding to different attributes of three-dimensional (3D) content. Each of the 2D data sets may provide attribute values for locations within a common 2D coordinate system that associates the attribute values for the different attributes with respective portions of the 3D content. The process may further generate a single 2D image by combining the 2D data sets. The attribute values corresponding to the different attributes may be combined with the single 2D image. The process may further encode the single 2D image into a specialized format for transmission or storage.
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公开(公告)号:US12075093B2
公开(公告)日:2024-08-27
申请号:US17951792
申请日:2022-09-23
Applicant: Apple Inc.
Inventor: Alexandros Tourapis , Hye-Yeon Cheong , David William Singer , Dominik Mehlem
IPC: H04N19/66 , H04N19/147 , H04N19/176 , H04N19/19 , H04N19/61 , G06T7/11 , G06T7/12
CPC classification number: H04N19/66 , H04N19/147 , H04N19/176 , H04N19/19 , H04N19/61 , G06T7/11 , G06T7/12
Abstract: A system comprises an encoder configured to compress media objects using a compression loop that includes a residual decomposition component that decomposes a residual signal for a block of the media object being compressed into multiple sub-error signals. The encoder is further configured to enable different transformation and/or quantization processes to be specified to be applied to different ones of the sub-errors. A corresponding decoder is configured to apply inverse transformation/quantization processing to the sub-error signals, based on the transformation/quantization processes that were applied at the encoder. The decoder then re-creates a residual signal from the processed sub-error signals and uses the re-created residual signal to correct predicted values at the decoder.
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公开(公告)号:US12063364B2
公开(公告)日:2024-08-13
申请号:US18239644
申请日:2023-08-29
Applicant: Apple Inc.
Inventor: Alexandros Tourapis , Guy Cote
IPC: H04N19/124 , H04N19/126 , H04N19/13 , H04N19/136 , H04N19/15 , H04N19/157 , H04N19/159 , H04N19/172 , H04N19/176 , H04N19/186 , H04N19/30 , H04N19/51 , H04N19/61 , H04N19/70 , H04N19/86 , H04N19/96
CPC classification number: H04N19/124 , H04N19/126 , H04N19/13 , H04N19/136 , H04N19/15 , H04N19/157 , H04N19/159 , H04N19/186 , H04N19/30 , H04N19/51 , H04N19/61 , H04N19/70 , H04N19/86 , H04N19/172 , H04N19/176 , H04N19/96
Abstract: A method of signaling additional chroma QP offset values that are specific to quantization groups is provided, in which each quantization group explicitly specifies its own set of chroma QP offset values. Alternatively, a table of possible sets of chroma QP offset values is specified in the header area of the picture, and each quantization group uses an index to select an entry from the table for determining its own set of chroma QP offset values. The quantization group specific chroma QP offset values are then used to determine the chroma QP values for blocks within the quantization group in addition to chroma QP offset values already specified for higher levels of the video coding hierarchy.
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公开(公告)号:US20240195978A1
公开(公告)日:2024-06-13
申请号:US18065220
申请日:2022-12-13
Applicant: Apple Inc.
Inventor: Yeqing WU , Yunfei Zheng , Alexandros Tourapis , Yixin Du , Alican Nalci , Hilmi E. Egilmez , Guoxin Jin , Jun Xin , Hsi-Jung Wu
IPC: H04N19/137 , H04N19/105 , H04N19/172 , H04N19/176
CPC classification number: H04N19/137 , H04N19/105 , H04N19/172 , H04N19/176
Abstract: The present disclosure describes techniques for efficient coding of motion vectors developed for multi-hypothesis coding applications. According to these techniques, when coding hypotheses are developed, each having a motion vector identifying a source of prediction for a current pixel block, a motion vector for a first one of the coding hypotheses may be predicted from the motion vector of a second coding hypothesis. The first motion vector may be represented by coding a motion vector residual, which represents a difference between the developed motion vector for the first coding hypothesis and the predicted motion vector for the first coding hypothesis, and outputting the coded residual to a channel. In another embodiment, a motion vector residual may be generated for a motion vector of a first coding hypothesis, and the first motion vector and the motion vector residual may be used to predict a second motion vector and a predicted motion vector residual. The second hypothesis's motion vector may be coded as a difference between the motion vector, the predicted second motion vector, and the predicted motion vector residual. In a further embodiment, a single motion vector residual may be output for the motion vectors of two coding hypotheses representing a difference between the motion vector of one of the hypotheses and a predicted motion vector for that hypothesis.
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公开(公告)号:US11962778B2
公开(公告)日:2024-04-16
申请号:US18136977
申请日:2023-04-20
Applicant: Apple Inc.
Inventor: Alexandros Tourapis , Guy Cote
IPC: H04N19/124 , H04N19/126 , H04N19/13 , H04N19/136 , H04N19/15 , H04N19/157 , H04N19/159 , H04N19/172 , H04N19/176 , H04N19/186 , H04N19/30 , H04N19/51 , H04N19/61 , H04N19/70 , H04N19/86 , H04N19/96
CPC classification number: H04N19/124 , H04N19/126 , H04N19/13 , H04N19/136 , H04N19/15 , H04N19/157 , H04N19/159 , H04N19/186 , H04N19/30 , H04N19/51 , H04N19/61 , H04N19/70 , H04N19/86 , H04N19/172 , H04N19/176 , H04N19/96
Abstract: A method of signaling additional chroma QP offset values that are specific to quantization groups is provided, in which each quantization group explicitly specifies its own set of chroma QP offset values. Alternatively, a table of possible sets of chroma QP offset values is specified in the header area of the picture, and each quantization group uses an index to select an entry from the table for determining its own set of chroma QP offset values. The quantization group specific chroma QP offset values are then used to determine the chroma QP values for blocks within the quantization group in addition to chroma QP offset values already specified for higher levels of the video coding hierarchy.
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公开(公告)号:US20240078738A1
公开(公告)日:2024-03-07
申请号:US18507377
申请日:2023-11-13
Applicant: Apple Inc.
Inventor: Khaled Mammou , Deepak S. Tolani , Alexandros Tourapis
Abstract: A system compresses and decompresses attribute information for visual volumetric content, such as a mesh representation. Attribute values are included in the visual volumetric representation, wherein at least some of the attribute values include unitary vectors, such as surface normal vectors or surface tangent vectors having a magnitude of one unit. In order to compress the attribute information the three-dimensional unit vectors are mapped into two dimensional parametric coordinates for a planar representation of a unit sphere. To reduce negative effects on compression due to distortion or discontinuities in the planar representation, mappings for compressing respective unit vectors are adaptively selected.
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公开(公告)号:US11887345B2
公开(公告)日:2024-01-30
申请号:US17225081
申请日:2021-04-07
Applicant: Apple Inc.
Inventor: Khaled Mammou , David Flynn , Alexandros Tourapis
IPC: G06T9/40
CPC classification number: G06T9/40
Abstract: A system receives encoded data regarding a points in a point cloud. The data includes a prediction tree having a nodes generated based on spatial information regarding the points and properties of a sensor system that obtained the spatial information. A value of each node represents first spatial coordinates of a respective one of the points according to a first coordinate system, and the value of at least a first node in the prediction tree is determined based on ancestor nodes of the first node and the properties of the sensor system. The system decodes the data to determine first data, including the first spatial coordinates of at least some of the points, and quantization parameters associated with the first spatial coordinates. The system determines second data based on the first data, including second spatial coordinates of at least some of the points according to a second coordinate system.
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