Patents by Inventor Alexandros Tourapis

Alexandros Tourapis has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20220239956
    Abstract: An encoder is configured to compress point cloud geometry information using an octree geometric compression technique that utilizes a binary arithmetic encoder, a look-ahead table, a cache, and a context selection process, wherein encoding contexts are selected based, at least in part, on neighborhood configurations. In a similar manner, a decoder is configured to decode compressed point cloud geometry information utilizing a binary arithmetic encoder, a look-ahead table, a cache, and a context selection process.
    Type: Application
    Filed: April 12, 2022
    Publication date: July 28, 2022
    Applicant: Apple Inc.
    Inventors: Alexandros Tourapis, Jungsun Kim, Valery G. Valentin, Fabrice A. Robinet, Yeping Su, Khaled Mammou
  • Patent number: 11398833
    Abstract: A system comprises an encoder configured to entropy encode a bitstream comprising both compressible and non-compressible symbols. The encoder parses the bitstream into a compressible symbol sub-stream and a non-compressible sub-stream. The non-compressible symbol sub-stream bypass an entropy encoding component of the encoder while the compressible symbol sub-stream is entropy encoded. When a quantity of bytes of entropy encoded symbols and bypass symbols is accumulated a chunk of fixed or known size is formed using the accumulated entropy encoded symbol bytes and the bypass bytes without waiting on the full bitstream to be processed by the encoder. In a complementary manner, a decoder reconstructs the bitstream from the packets or chunks.
    Type: Grant
    Filed: October 1, 2020
    Date of Patent: July 26, 2022
    Assignee: Apple Inc.
    Inventors: David Flynn, Alexandros Tourapis, Khaled Mammou
  • Patent number: 11395008
    Abstract: A system comprises an encoder configured to compress video data using an in-loop noise generation process that generates noise in the compression loop at a sub-image portion level of granularity, such as at a block level. The encoder includes noise model and/or noise model input parameter information in an encoded bit stream. Also, a system includes a decoder configured to receive such a bit stream and decompress the video using an in-loop noise generation process that generates noise in the decompression loop at a sub-image portion level of granularity.
    Type: Grant
    Filed: September 23, 2020
    Date of Patent: July 19, 2022
    Assignee: Apple Inc.
    Inventors: Hye-Yeon Cheong, David W. Singer, Alexandros Tourapis
  • Patent number: 11386524
    Abstract: A system comprises an encoder configured to compress attribute information and/or spatial for a point cloud and/or a decoder configured to decompress compressed attribute and/or spatial information for the point cloud. The encoder is configured to convert a point cloud into an image based representation. The encoder packs patch images into an image frame and fills empty spaces in the image frame with a padding, wherein pixel values for the padding are determined based on neighboring pixels values such that the padding is smoothed in the image frame. Also, the decoder is configured to generate a decompressed point cloud based on an image based representation of a point cloud.
    Type: Grant
    Filed: September 27, 2019
    Date of Patent: July 12, 2022
    Assignee: Apple Inc.
    Inventors: Khaled Mammou, Alexandros Tourapis, Jungsun Kim, Yeping Su, David W. Singer, Valery G. Valentin, Fabrice A. Robinet
  • Patent number: 11388419
    Abstract: Improved video coding techniques include 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.
    Type: Grant
    Filed: March 30, 2020
    Date of Patent: July 12, 2022
    Assignee: Apple inc.
    Inventors: Mei Guo, Jun Xin, Hsi-Jung Wu, Alexandros Tourapis, Krishnakanth Rapaka
  • Patent number: 11368689
    Abstract: An encoder system may include an analyzer that analyzes a current image area in an input video to select a transform. A selectable residue transformer, controlled by the analyzer, may perform the selectable transform on a residue image generated from the current image area and a predicted current image area, to generate a transformed residue image. An encoder may encode the transformed residue image to generate output data. The analyzer controls the encoder to encode information to identify the selectable transform and to indicate that the selectable transform for the current image area is different from a transform of a previous image area of the input video. A decoder system may include components appropriate for decoding the output data from the encoder system.
    Type: Grant
    Filed: March 18, 2020
    Date of Patent: June 21, 2022
    Assignee: Apple Inc.
    Inventor: Alexandros Tourapis
  • Patent number: 11368688
    Abstract: An encoder system may include an analyzer that analyzes a current image area in an input video to select a transform. A selectable residue transformer, controlled by the analyzer, may perform the selectable transform on a residue image generated from the current image area and a predicted current image area, to generate a transformed residue image. An encoder may encode the transformed residue image to generate output data. The analyzer controls the encoder to encode information to identify the selectable transform and to indicate that the selectable transform for the current image area is different from a transform of a previous image area of the input video. A decoder system may include components appropriate for decoding the output data from the encoder system.
    Type: Grant
    Filed: March 3, 2020
    Date of Patent: June 21, 2022
    Assignee: Apple Inc.
    Inventor: Alexandros Tourapis
  • Patent number: 11367224
    Abstract: A system comprises an encoder configured to compress attribute information and/or spatial information for a point cloud and/or a decoder configured to decompress compressed attribute and/or spatial information for the point cloud. The encoder is configured to convert a point cloud into an image based representation. The encoder packs patch images into an image frame and fills empty spaces in the image frame with a padding. Various compression strategies may be used to encode an occupancy map and related block-to-patch information indicating which portions of the image frame correspond to which packed patches. Packed image frames comprising patches and padding, along with an encoded occupancy map and related block-to-patch information are sent to a decoder. The decoder is configured to generate a decompressed point cloud based on the packed image frames, compressed occupancy map, and related block-to-patch information.
    Type: Grant
    Filed: October 2, 2019
    Date of Patent: June 21, 2022
    Assignee: Apple Inc.
    Inventors: Khaled Mammou, Alexandros Tourapis, Yeping Su, Jungsun Kim, Fabrice A Robinet, Valery G. Valentin
  • Publication number: 20220191493
    Abstract: Embodiments feature families of rate allocation and rate control methods that utilize advanced processing of past and future frame/field picture statistics and are designed to operate with one or more coding passes. At least two method families include: a family of methods for a rate allocation with picture look-ahead; and a family of methods for average bit rate (ABR) control methods. At least two other methods for each method family are described. For the first family of methods, some methods may involve intra rate control. For the second family of methods, some methods may involve high complexity ABR control and/or low complexity ABR control. These and other embodiments can involve any of the following: spatial coding parameter adaptation, coding prediction, complexity processing, complexity estimation, complexity filtering, bit rate considerations, quality considerations, coding parameter allocation, and/or hierarchical prediction structures, among others.
    Type: Application
    Filed: December 21, 2021
    Publication date: June 16, 2022
    Inventors: Athanasios Leontaris, Alexandros Tourapis
  • Patent number: 11361471
    Abstract: A system comprises an encoder configured to compress attribute information and/or spatial for a point cloud and/or a decoder configured to decompress compressed attribute and/or spatial information for the point cloud. To compress the attribute and/or spatial information, the encoder is configured to convert a point cloud into an image based representation. Also, the decoder is configured to generate a decompressed point cloud based on an image based representation of a point cloud. A block/sub-block organization scheme is used to encode blocks and sub-blocks of an occupancy map used in compressing the point cloud. Binary values are assigned to blocks/sub-blocks based on whether they contain patches projected on the point cloud. A traversal path is chosen that takes advantage of run-length encoding strategies to reduce a size of an encoded occupancy map. Also, auxiliary information is used to further improve occupancy map compression.
    Type: Grant
    Filed: May 13, 2020
    Date of Patent: June 14, 2022
    Assignee: Apple Inc.
    Inventors: Khaled Mammou, Yeping Su, David W. Singer, Alexandros Tourapis, Fabrice A. Robinet, Hsi-Jung Wu
  • Patent number: 11363309
    Abstract: An encoder is configured to compress point cloud geometry information using an octree geometric compression technique that utilizes a binary arithmetic encoder, a look-ahead table, a cache, and a context selection process, wherein encoding contexts are selected based, at least in part, on neighborhood configurations. In a similar manner, a decoder is configured to decode compressed point cloud geometry information utilizing a binary arithmetic encoder, a look-ahead table, a cache, and a context selection process.
    Type: Grant
    Filed: October 9, 2020
    Date of Patent: June 14, 2022
    Assignee: Apple Inc.
    Inventors: Alexandros Tourapis, Jungsun Kim, Valery G. Valentin, Fabrice A. Robinet, Yeping Su, Khaled Mammou
  • Patent number: 11363264
    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.
    Type: Grant
    Filed: May 21, 2020
    Date of Patent: June 14, 2022
    Assignee: Apple Inc.
    Inventor: Alexandros Tourapis
  • Patent number: 11348284
    Abstract: A system comprises an encoder configured to compress attribute information and/or spatial information for a point cloud and/or a decoder configured to decompress compressed attribute and/or spatial information for the point cloud. The encoder is configured to convert a point cloud into an image based representation. The encoder packs patch images into an image frame and fills empty spaces in the image frame with a padding. Auxiliary information is signaled for use in identifying patches in an image frame. The auxiliary information may be signaled using a syntax that includes a header portion and data portion, which may enable temporal prediction and timing information to be signaled.
    Type: Grant
    Filed: January 7, 2020
    Date of Patent: May 31, 2022
    Assignee: Apple Inc.
    Inventors: Alexandros Tourapis, Jungsun Kim, Khaled Mammou
  • Publication number: 20220166969
    Abstract: Techniques for encoding video with motion compensation include a compressed bitstream syntax that includes a list of all motion prediction reference frames without distinguishing between short-term reference frame and long-term reference frames. The list of reference frames may be provided in a slice header and may apply to encoded data video data within the corresponding slice. The list may be prefaced with a single number indicating the total number of reference frames. In an aspect delta POC reference numbers may be encoded with a flag indicating the sign of the delta POC when the absolute value of the POC is not equal to zero. In another aspect, a flag may be encoded for every reference frame indicating if POC information should be used when scaling prediction references, and a weighting parameter may be included when POC information should be used.
    Type: Application
    Filed: December 2, 2021
    Publication date: May 26, 2022
    Inventors: Alexandros Tourapis, Jungsun Kim, Krishnakanth Rapaka, David W. Singer
  • Publication number: 20220167006
    Abstract: Several improvements for use with Bidirectionally Predictive (B) pictures within a video sequence are provided. In certain improvements Direct Mode encoding and/or Motion Vector Prediction are enhanced using spatial prediction techniques. In other improvements Motion Vector prediction includes temporal distance and subblock information, for example, for more accurate prediction. Such improvements and other presented herein significantly improve the performance of any applicable video coding system/logic.
    Type: Application
    Filed: February 10, 2022
    Publication date: May 26, 2022
    Applicant: Microsoft Technology Licensing, LLC
    Inventors: Alexandros Tourapis, Shipeng Li, Feng Wu
  • Patent number: 11336913
    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.
    Type: Grant
    Filed: February 24, 2020
    Date of Patent: May 17, 2022
    Assignee: Apple Inc.
    Inventors: Krishnakanth Rapaka, Alexandros Tourapis, David W. Singer
  • Patent number: 11323730
    Abstract: Techniques for video exchange are disclosed in which a video source sends redundant copies of video coded at a given presentation time. A decoder may determine, from metadata stored with a first decoded frame, whether other decoded frames have been designated as correlated to the first decoded frame. If so, the decoder may fetch other decoding frames using time indicator values of other decoded frames in metadata stored with the first decoded frame. When other decoded frame(s) are found, the decoder may blend content of the first coded frame and the other decoded frame(s). The decoder may render the blended frame. When one such coded frame is an intra-coded frame, the proposed technique may alleviate beating artifacts by blending recovered data of the intra-coded frame with recovered data of another frame, which may be inter-coded.
    Type: Grant
    Filed: September 5, 2019
    Date of Patent: May 3, 2022
    Assignee: Apple Inc.
    Inventors: Mei Guo, Jun Xin, Yeping Su, Hsi-Jung Wu, Alexandros Tourapis
  • Publication number: 20220109857
    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.
    Type: Application
    Filed: December 17, 2021
    Publication date: April 7, 2022
    Inventors: Alexandros Tourapis, Athanasios Leontaris
  • Publication number: 20220109874
    Abstract: Sampled data is packaged in checkerboard format for encoding and decoding. The sampled data may be quincunx sampled multi-image video data (e.g., 3D video or a multi-program stream), and the data may also be divided into sub-images of each image which are then multiplexed, or interleaved, in frames of a video stream to be encoded and then decoded using a standardized video encoder. A system for viewing may utilize a standard video decoder and a formatting device that de-interleaves the decoded sub-images of each frame reformats the images for a display device. A 3D video may be encoded using a most advantageous interleaving format such that a preferred quality and compression ratio is reached. In one embodiment, the invention includes a display device that accepts data in multiple formats.
    Type: Application
    Filed: December 16, 2021
    Publication date: April 7, 2022
    Applicant: Dolby Laboratories Licensing Corporation
    Inventors: Alexandros Tourapis, Walter J. Husak, Peshala V. Pahalawatta, Athanasios Leontaris
  • Publication number: 20220103851
    Abstract: Video compression and decompression techniques are disclosed that provide improved bandwidth control for video compression and decompression systems. In particular, video coding and decoding techniques quantize input video in multiple dimensions. According to these techniques, pixel residuals may be generated from a comparison of an array of input data to an array of prediction data. The pixel residuals may be quantized in a first dimension. After the quantization, the quantized pixel residuals may be transformed to an array of transform coefficients. The transform coefficients may be quantized in a second dimension and entropy coded. Decoding techniques invert these processes. In still other embodiments, multiple quantizers may be provided upstream of the transform stage, either in parallel or in cascade, which provide greater flexibility to video coders to quantize data in different dimensions in an effort to balance the competing interest in compression efficiency and quality of reconstructed video.
    Type: Application
    Filed: October 4, 2021
    Publication date: March 31, 2022
    Inventors: Alexandros Tourapis, Yeping Su, David Singer, Hsi-Jung Wu