MOTION FIELD ESTIMATION BASED ON MOTION TRAJECTORY DERIVATION

    公开(公告)号:US20240171733A1

    公开(公告)日:2024-05-23

    申请号:US18424445

    申请日:2024-01-26

    Applicant: GOOGLE LLC

    CPC classification number: H04N19/105 H04N19/139 H04N19/172 H04N19/573

    Abstract: A motion field estimate determined using motion vector information of two or more reference frames of a current/encoded frame is used to derive a motion vector for inter-prediction of the current/encoded frame. Motion trajectory information, including concatenated motion vectors and locations of the current/encoded frame at which those concatenated motion vectors point, is determined by concatenating motion vectors of the reference frames. A motion field estimate is determined using the motion trajectory information and, in some cases, by interpolating unavailable motion vectors using neighbors. The motion field estimate is used to determine a co-located reference frame for the current/encoded frame, and an inter-prediction process is performed for the current/encoded frame using a motion vector derived using the co-located reference frame. During decoding, the motion field estimate may be determined using motion vectors signaled within a bitstream and without additional side information, thereby improving prediction coding efficiency.

    DEBLOCKING FILTERING
    83.
    发明公开

    公开(公告)号:US20240155121A1

    公开(公告)日:2024-05-09

    申请号:US18406816

    申请日:2024-01-08

    Applicant: Google LLC

    CPC classification number: H04N19/117 H04N19/176 H04N19/186 H04N19/46

    Abstract: A bitstream that stores encoded image data is described. In addition to the compressed data for color planes of the image, signals identifying respective deblocking filters is identified for the different color planes of the image. The deblocking filters may include those having different lengths for a luma plane as compared to one or more chroma planes of the image. One or more of the color planes, such as the luma plane, may have different filters for filtering reconstructed pixels vertically as compared to filtering the reconstructed pixels horizontally.

    CONSTRAINED MOTION FIELD ESTIMATION FOR HARDWARE EFFICIENCY

    公开(公告)号:US20220377364A1

    公开(公告)日:2022-11-24

    申请号:US17868011

    申请日:2022-07-19

    Applicant: GOOGLE LLC

    Abstract: Decoding a current block of a current frame includes obtaining motion trajectories between the current frame and at least one previously coded frame by projecting motion vectors from the at least one previously coded frame onto the current frame. A motion field is obtained between the current frame and a reference frame used for coding the current frame. The motion field is obtained by extending the motion trajectories from the current frame towards the reference frame. A motion vector for the current block is identified based on the motion field. A prediction block is obtained for the current block using a reference block of the reference frame identified using the motion vector.

    Constrained motion field estimation for hardware efficiency

    公开(公告)号:US11405631B2

    公开(公告)日:2022-08-02

    申请号:US16983342

    申请日:2020-08-03

    Applicant: GOOGLE LLC

    Abstract: Decoding a current frame includes identifying a first reference frame and a second reference frame for decoding the current frame; storing reference motion vectors of reference blocks of the first reference frame, where other reference frames are used to decode the first reference frame; identifying motion trajectories that pass through the current frame by projecting the reference motion vectors of the reference blocks of the first reference frame onto the current frame using at least a third reference frame of the other reference frames, where the projecting identifies, for a first current block of the current frame a corresponding first reference block in the first reference frame, and a corresponding reference motion vector of the reference motion vectors is associated with the corresponding first reference block; and projecting the corresponding reference motion vector onto the second reference frame to obtain a second reference block in the second reference frame.

    Asymmetric probability model update and entropy coding precision

    公开(公告)号:US11218737B2

    公开(公告)日:2022-01-04

    申请号:US16042261

    申请日:2018-07-23

    Applicant: GOOGLE LLC

    Abstract: Asymmetric probability model updating and entropy coding includes using different numbers of bits for storing probabilities of a probability model and for entropy coding symbols using that probability model. The probabilities of a probability model are updated according to values of syntax elements decoded from a bitstream. The probabilities are associated with possible values of the syntax elements and are stored using a first bit precision. Based on the updated probabilities, a second bit precision to use to entropy decode the syntax elements is determined. The second bit precision is less than the first bit precision. The syntax elements are then entropy decoded using the second bit precision, such as to produce quantized transform coefficients, which may be further processed and output to an output video stream. Using the first bit precision to entropy decode the syntax elements results in a lower compression throughput than using the second bit precision.

    DC coefficient sign coding scheme
    87.
    发明授权

    公开(公告)号:US11102477B2

    公开(公告)日:2021-08-24

    申请号:US16838544

    申请日:2020-04-02

    Applicant: GOOGLE LLC

    Abstract: A sign value of a DC coefficient of a current block is determined using neighbor blocks of the current block. First and second sign values are identified as respectively corresponding to an above neighbor block of the current block and a left neighbor block of the current block. A context value is calculated by applying a first weighting value to the first sign value and a second weighting value to the second sign value. The first weighting value is based on a boundary between the above neighbor block and the current block, and the second weighting value is based on a boundary between the left neighbor block and the current block. A probability value is selected based on the context value. The sign value of the DC coefficient of the current block is then determined using the probability model.

    Motion Field Estimation Based on Motion Trajectory Derivation

    公开(公告)号:US20210144364A1

    公开(公告)日:2021-05-13

    申请号:US17090094

    申请日:2020-11-05

    Applicant: GOOGLE LLC

    Abstract: A motion field estimate determined using motion vector information of two or more reference frames of a current/encoded frame is used to derive a motion vector for inter-prediction of the current/encoded frame. Motion trajectory information, including concatenated motion vectors and locations of the current/encoded frame at which those concatenated motion vectors point, is determined by concatenating motion vectors of the reference frames. A motion field estimate is determined using the motion trajectory information and, in some cases, by interpolating unavailable motion vectors using neighbors. The motion field estimate is used to determine a co-located reference frame for the current/encoded frame, and an inter-prediction process is performed for the current/encoded frame using a motion vector derived using the co-located reference frame. During decoding, the motion field estimate may be determined using motion vectors signaled within a bitstream and without additional side information, thereby improving prediction coding efficiency.

    BLOCK-BASED Optical Flow Estimation FOR MOTION COMPENSATED PREDICTION IN VIDEO CODING

    公开(公告)号:US20200267391A1

    公开(公告)日:2020-08-20

    申请号:US16866591

    申请日:2020-05-05

    Applicant: GOOGLE LLC

    Abstract: Decoding a current block of a current frame includes selecting a first reference frame for forward inter prediction of the current frame; selecting a second reference frame for backward inter prediction of the current frame; generating an optical flow reference frame portion for inter prediction of the current block by performing an optical flow estimation using the first reference frame and the second reference frame, where the optical flow estimation produces a respective motion field for pixels of the current block; and performing a prediction process for the current block using the optical flow reference frame portion by: using a motion vector used to encode the current block to identify a reference block; adjusting boundaries of the reference block using a subpixel interpolation filter length; and identifying blocks encompassing pixels within the adjusted boundaries of the reference block.

    DUAL DEBLOCKING FILTER THRESHOLDS
    90.
    发明申请

    公开(公告)号:US20200236375A1

    公开(公告)日:2020-07-23

    申请号:US16838529

    申请日:2020-04-02

    Applicant: GOOGLE LLC

    Abstract: An apparatus for video coding using dual deblocking filter thresholds may include a processor generating a reconstructed frame by decoding an encoded bitstream and outputting the reconstructed frame. Decoding may include generating a decoded block by decoding a portion of the encoded bitstream, identifying a first deblocking threshold index from the encoded bitstream, identifying a second deblocking threshold index from the encoded bitstream, generating a reconstructed block based on the decoded block, and including the reconstructed block in the reconstructed frame. Generating the reconstructed block may include deblocking based on the first deblocking threshold index and the second deblocking threshold index.

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