Deep Quality Enhancement of Adaptive Downscaled Coding for Image Compression

    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.

    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.

    Method and Device for Generating Metadata Estimations based on Metadata Subdivisions

    公开(公告)号:US20240104766A1

    公开(公告)日:2024-03-28

    申请号:US18369354

    申请日:2023-09-18

    Applicant: Apple Inc.

    Abstract: In one implementation, a method is performed for generating metadata estimations based on metadata subdivisions. The method includes: obtaining an input image; obtaining metadata associated with the input image; subdividing the metadata into a plurality of metadata subdivisions; determining a viewport relative to the input image based on at least one of head pose information and eye tracking information; generating one or more metadata estimations by performing an estimation algorithm on at least a portion of the plurality of metadata subdivisions based on the viewport; and generating an output image by performing an image processing algorithm on the input image based on the one or more metadata estimations.

    TECHNIQUES FOR REDUCING CODING ARTIFACTS IN CODING SYSTEM

    公开(公告)号:US20230070492A1

    公开(公告)日:2023-03-09

    申请号:US17886858

    申请日:2022-08-12

    Applicant: Apple Inc.

    Abstract: Techniques for reducing reduce coding artifacts in video data are disclosed. In one aspect, a frame of video data is partitioned into pixel blocks, which are organized into slices. The pixel blocks of each slice are coded by a compression algorithm and an estimate of coding artifacts in the slice is made. For slices that are estimated to possess coding artifacts, the method revises coding parameters applied to pixel blocks in the slice and recodes the slice. The method substitutes recoded slices for originally-coded slices in frame, working in a priority order from a slice with the highest estimated likelihood of coding artifacts down to slices with lower estimated likelihoods of coding artifacts, measuring changes in the frame's coding size as it goes. The likelihood of coding artifacts can be estimated from slice statistics that may be developed from a comparison of transform coefficients among the pixel blocks within a slice, from an evaluation of transform coefficients of a pixel block with a slice that is estimated to have a lowest spatial complexity, or from coded luma data of the pixel blocks within a slice. In a further aspect, slice statistics may be computed from pixel block data only for a subset of slices within a frame. Slice statistics for other slices may be derived from the statistics of neighboring slices. In another aspect, a method may revise coding parameters in iterative fashion working from an initialized value and estimate (without recoding them) data sizes of coded slices that may be obtained from the revised parameters. As the method operates, it may compare the coding parameters to parameters used in a first iteration of coding and terminate the iterative process for that slice if the first iteration coding parameters are higher than the revised parameter.

    Ambient headroom adaptation
    20.
    发明授权

    公开(公告)号:US11473971B2

    公开(公告)日:2022-10-18

    申请号:US16586411

    申请日:2019-09-27

    Applicant: Apple Inc.

    Abstract: A device comprises memory, a display characterized by a display characteristic, and processors coupled to the memory. The processors execute instructions causing the processors to receive data indicative of the display characteristic, data indicative of ambient lighting, and data indicative of content characteristics for a content item; determine a tone mapping curve for the content item based on the data indicative of content characteristics; determine a first, so-called “anchor” point along the tone mapping curve; modify a first portion of the tone mapping curve below the anchor point based on the data indicative of ambient lighting; modify a second portion of the tone mapping curve above the anchor point based on the data indicative of the display characteristic; perform tone mapping for the content item based on the modified toned mapping curve to obtain a tone mapped content item; and cause the display to display the tone mapped content item.

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