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公开(公告)号:US20200053362A1
公开(公告)日:2020-02-13
申请号:US16100310
申请日:2018-08-10
Applicant: Apple Inc.
Inventor: Xiang Fu , Linfeng Guo , Haiyan He , Wei Li , Xu Gang Zhao , Hao Pan , Xiaohua Yang , Krishnakanth Rapaka , Munehiro Nakazato , Haitao Guo
IPC: H04N19/176 , H04N19/126 , G06N3/08 , G06T7/13
Abstract: Techniques are disclosed for coding image data adaptively at different levels of downscaling. Such techniques may involve partitioning input data into pixel blocks for coding and performing content analysis on the pixel blocks. The pixel blocks may be input to block coders that operate at different pixel block sizes, which may code the pixel blocks input to them at their respective sizes. Except when a block coder operates at the partitioning size, block coders that operate at different pixel block sizes may perform downscaling of the pixel blocks to match their size with the block coders' respective coding size. A block decoder may invert the coding operations performed by the block coders, decoding coded image data at respective pixel block sizes, then upscaling decoded image data obtained therefrom to a common pixel block size. Image reconstruction may synthesize a resultant image from the decode pixel block data output by the decoders. Quality enhancements may be added by neural network processing systems that have been trained to other segmented images.
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公开(公告)号:US12267506B2
公开(公告)日:2025-04-01
申请号:US17837846
申请日:2022-06-10
Applicant: Apple Inc.
Inventor: Mei Guo , Jun Xin , Hsi-Jung Wu , Alexandros Tourapis , Krishnakanth Rapaka
IPC: H04N19/159 , H04N19/176 , H04N19/182
Abstract: Techniques are disclosed for deriving prediction pixel blocks for use in intra-coding video and combined inter- and intra-coding video. In a first aspect, the techniques may include deriving value(s) for pixel location(s) of the prediction pixel block by, when a prediction direction vector assigned to the prediction vector points to quadrants I or III of a Cartesian plane, deriving the pixel location's value from pixel values in two regions of previously-decoded pixel data intercepted by extending the prediction direction vector in two opposite directions through the pixel location. When the prediction direction vector points toward quadrants II of the Cartesian plane, deriving the pixel location's value from pixel values in one region intercepted by the prediction direction vector through the pixel location, and from a second region intercepted by a vector that is orthogonal to the prediction direction vector.
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公开(公告)号:US20250024034A1
公开(公告)日:2025-01-16
申请号:US18900600
申请日:2024-09-27
Applicant: Apple Inc.
Inventor: Alexandros Tourapis , Krishnakanth Rapaka , Dominik Mehlem
IPC: H04N19/117 , H04N19/126 , H04N19/13 , H04N19/182 , H04N19/82
Abstract: A system comprises an encoder configured to compress video data. The encoder includes an adaptive bilateral filter that uses look-up tables. The encoder may encode one or more adaptive adjustment factors to be used by a decoder to select or adjust look-up tables used to decode the compressed video data.
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公开(公告)号:US11979572B2
公开(公告)日:2024-05-07
申请号:US17234596
申请日:2021-04-19
Applicant: Apple Inc.
Inventor: Krishnakanth Rapaka , Jaehong Chon , Alexandros Tourapis , David W. Singer
IPC: H04N19/124 , H04N19/172 , H04N19/186 , H04N19/82
CPC classification number: H04N19/124 , H04N19/172 , H04N19/186 , H04N19/82
Abstract: Improved video coding and decoding techniques are described, including techniques to derive quantization step sizes adaptively with quantization step size table templates. Quantization techniques described provide finer-grained control over quantization with a more flexible quantization step size especially at higher degrees of quantization. This may result in improved overall compression quality. Other coding parameters, such as in-loop filtering parameters, may be derived based on the more flexible quantization parameters.
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公开(公告)号:US20210136370A1
公开(公告)日:2021-05-06
申请号:US16834611
申请日:2020-03-30
Applicant: Apple Inc.
Inventor: Alexandros Tourapis , David W. Singer , Dominik Mehlem , Krishnakanth Rapaka
IPC: H04N19/119 , H04N19/159 , H04N19/139 , H04N19/176 , H04N19/573 , H04N19/543
Abstract: Techniques for coding and decoding video may include predicting picture regions defined by a time-varying tessellation and/or by a tessellation that varies spatially within a picture. These techniques improve decoded video quality, for example, by reducing block-based visual artifacts. Tessellation patterns may be irregular spatially to prevent alignment of some prediction region boundaries within a picture. Tessellation patterns may vary over time based on a spatial offset value, and the spatial offset value may be determined via a modulo function. Tessellation patterns may include overlapped shapes, for example when used in conjunction with overlapped block motion compensation.
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公开(公告)号:US10764588B2
公开(公告)日:2020-09-01
申请号:US16100310
申请日:2018-08-10
Applicant: Apple Inc.
Inventor: Xiang Fu , Linfeng Guo , Haiyan He , Wei Li , Xu Gang Zhao , Hao Pan , Xiaohua Yang , Krishnakanth Rapaka , Munehiro Nakazato , Haitao Guo
IPC: H04N19/176 , H04N19/126 , G06T7/13 , G06N3/08
Abstract: Techniques are disclosed for coding image data adaptively at different levels of downscaling. Such techniques may involve partitioning input data into pixel blocks for coding and performing content analysis on the pixel blocks. The pixel blocks may be input to block coders that operate at different pixel block sizes, which may code the pixel blocks input to them at their respective sizes. Except when a block coder operates at the partitioning size, block coders that operate at different pixel block sizes may perform downscaling of the pixel blocks to match their size with the block coders' respective coding size. A block decoder may invert the coding operations performed by the block coders, decoding coded image data at respective pixel block sizes, then upscaling decoded image data obtained therefrom to a common pixel block size. Image reconstruction may synthesize a resultant image from the decode pixel block data output by the decoders. Quality enhancements may be added by neural network processing systems that have been trained to other segmented images.
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公开(公告)号:US12058361B2
公开(公告)日:2024-08-06
申请号:US17723788
申请日:2022-04-19
Applicant: Apple Inc.
Inventor: Krishnakanth Rapaka , Alexandros Tourapis , David W. Singer
IPC: H04N19/503 , H04N19/82 , H04N19/86
CPC classification number: H04N19/503 , H04N19/82 , H04N19/86
Abstract: Predictive coding techniques may include resampling of reference pictures, where various coding parameters are determined based on the resolution(s) or pixel format(s) of the prediction references. In a first aspect, lists of weights for use in weighted prediction are based on the resolution(s) of prediction references. In a second aspect, resampling filter parameters are selected based on the resolutions of prediction references. In a third aspect, deblocking filter parameters are based on the resolution(s) of prediction references.
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公开(公告)号:US11871052B1
公开(公告)日:2024-01-09
申请号:US16580184
申请日:2019-09-24
Applicant: Apple Inc.
Inventor: Hao Pan , Haitao Guo , Ke Chen , Francesco Iacopino , Jim C. Chou , Xiaohua Yang , Linfeng Guo , Munehiro Nakazato , Krishnakanth Rapaka , Ye Cong
IPC: G06F15/16 , H04N21/2343 , G02B27/00 , G06T19/00 , H04N21/2662
CPC classification number: H04N21/2343 , G02B27/0093 , G06T19/006 , H04N21/2662
Abstract: In one implementation, a method of generating a bit stream encoding a video stream is performed by a device including one or more processors and non-transitory memory. The method includes decomposing a video stream into a plurality of frequency band video streams. The method includes determining a target bitrate and determining, for each frequency band video stream, a respective frequency band bit rate based on the target bit rate. The method includes encoding each of the plurality of frequency band video streams at its respective frequency band bit rate and transmitting, over a channel, each encoded frequency band video stream.
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公开(公告)号:US11758133B2
公开(公告)日:2023-09-12
申请号:US16834611
申请日:2020-03-30
Applicant: Apple Inc.
Inventor: Alexandros Tourapis , David W. Singer , Dominik Mehlem , Krishnakanth Rapaka
IPC: H04N19/119 , H04N19/159 , H04N19/543 , H04N19/176 , H04N19/573 , H04N19/139
CPC classification number: H04N19/119 , H04N19/139 , H04N19/159 , H04N19/176 , H04N19/543 , H04N19/573
Abstract: Techniques for coding and decoding video may include predicting picture regions defined by a time-varying tessellation and/or by a tessellation that varies spatially within a picture. These techniques improve decoded video quality, for example, by reducing block-based visual artifacts. Tessellation patterns may be irregular spatially to prevent alignment of some prediction region boundaries within a picture. Tessellation patterns may vary over time based on a spatial offset value, and the spatial offset value may be determined via a modulo function. Tessellation patterns may include overlapped shapes, for example when used in conjunction with overlapped block motion compensation.
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公开(公告)号:US20220329805A1
公开(公告)日:2022-10-13
申请号:US17843160
申请日:2022-06-17
Applicant: Apple Inc.
Inventor: Krishnakanth Rapaka , Munehiro Nakazato , Jiandong Shen , Ganesh G. Yadav , Sorin Constantin Cismas , Jim C. Chou , Hao Pan
IPC: H04N19/124 , H04N19/60
Abstract: In one implementation, a method of encoding an image is performed at a device including one or more processors and non-transitory memory. The method includes determining a category of a spatial portion of an image based on a relation between a plurality of thresholds associated with a plurality of quantization scaling parameters and a bit rate of the spatial portion of the image at the plurality of quantization scaling parameters. The method includes quantizing the spatial portion of the image based on the categorization.
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