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: 20230076939
    Abstract: In an example method, a system obtains first data representing a plurality of polygons of a polygon mesh, and performs several operations for each of the polygons, including (i) determining a number of sample points for that polygon, where the number of sample points is determined based on at least one of an area of that polygon or an area of the polygon mesh, (ii) determining a distribution of the sample points for that polygon, and (iii) sampling the polygon mesh in accordance with the determined number of sample points and the determined distribution of sample points, where sampling the polygon mesh includes determining one or more characteristics of the polygon mesh at each of the sample points. The system also outputs second data representing the one or more characteristics of the polygon mesh at one or more of the sample points.
    Type: Application
    Filed: September 9, 2022
    Publication date: March 9, 2023
    Inventors: Khaled Mammou, Alexandros Tourapis, Arnold H. Cachelin, David Flynn, Fabrice A. Robinet, Jungsun Kim
  • Publication number: 20230072818
    Abstract: A system comprises an encoder configured to compress attribute information for a point cloud and/or a decoder configured to decompress compressed attribute information. Attribute values for at least one starting point are included in a compressed attribute information file and attribute correction values are included in the compressed attribute information file. An order for the points is determined based on a space filling curve, wherein an encoder and a decoder determine a same order for the points based on the space filling curve. Levels of detail are determined by sampling the ordered points according to different sampling parameters, and attribute values are predicted for the points in the levels of detail using the determined order. The encoder determines attribute correction values based on a comparison of the predicted values to an original value prior to compression. The decoder corrects the predicted attribute values based on received attribute correction values.
    Type: Application
    Filed: September 23, 2022
    Publication date: March 9, 2023
    Applicant: Apple Inc.
    Inventors: Khaled Mammou, Alexandros Tourapis, Jungsun Kim
  • Patent number: 11582465
    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: Grant
    Filed: December 17, 2021
    Date of Patent: February 14, 2023
    Assignee: APPLE, INC.
    Inventors: Alexandros Tourapis, Athanasios Leontaris
  • Patent number: 11575934
    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: Grant
    Filed: February 10, 2022
    Date of Patent: February 7, 2023
    Assignee: Microsoft Technology Licensing, LLC
    Inventors: Alexandros Tourapis, Shipeng Li, Feng Wu
  • Publication number: 20230030913
    Abstract: A system comprises an encoder configured to compress and encode data for a three-dimensional mesh using a video encoding technique. To compress the three-dimensional mesh, the encoder determines sub-meshes and for each sub-mesh: texture patches and geometry patches. Also the encoder determines patch connectivity information and patch texture coordinates for the texture patches and geometry patches. The texture patches and geometry patches are packed into video image frames and encoded using a video codec. Additionally, the encoder determines boundary stitching information for the sub-meshes. A decoder receives a bit stream as generated by the encoder and reconstructs the three-dimensional mesh.
    Type: Application
    Filed: September 16, 2022
    Publication date: February 2, 2023
    Applicant: Apple Inc.
    Inventors: Khaled Mammou, Alexandros Tourapis, Jungsun Kim
  • Patent number: 11562507
    Abstract: A system comprises an encoder configured to compress attribute 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. 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. In some embodiments, an encoder generates time-consistent patches for multiple version of the point cloud at multiple moments in time and uses the time-consistent patches to generate image based representations of the point cloud at the multiple moments in time.
    Type: Grant
    Filed: September 24, 2020
    Date of Patent: January 24, 2023
    Assignee: Apple Inc.
    Inventors: Jungsun Kim, Alexandros Tourapis, Khaled Mammou, Chao Cao, Marius Preda
  • Publication number: 20230009225
    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.
    Type: Application
    Filed: September 23, 2022
    Publication date: January 12, 2023
    Inventors: Alexandros Tourapis, Hye-Yeon Cheong, David William Singer, Dominik Mehlem
  • Patent number: 11552651
    Abstract: A system comprises an encoder configured to compress attribute information for a point cloud and/or a decoder configured to decompress compressed attribute information for the point cloud. Attribute values for at least one starting point are included in a compressed attribute information file and attribute correction values used to correct predicted attribute values are included in the compressed attribute information file. Attribute values are predicted based, at least in part, on attribute values of neighboring points and distances between a particular point for whom an attribute value is being predicted and the neighboring points. The predicted attribute values are compared to attribute values of a point cloud prior to compression to determine attribute correction values. A decoder follows a similar prediction process as an encoder and corrects predicted values using attribute correction values included in a compressed attribute information file.
    Type: Grant
    Filed: December 23, 2020
    Date of Patent: January 10, 2023
    Assignee: Apple Inc.
    Inventors: Khaled Mammou, Fabrice A. Robinet, Alexandros Tourapis, Yeping Su
  • Publication number: 20230007302
    Abstract: An encoding device evaluates a plurality of processing and/or post-processing algorithms and/or methods to be applied to a video stream, and signals a selected method, algorithm, class or category of methods/algorithms either in an encoded bitstream or as side information related to the encoded bitstream. A decoding device or post-processor utilizes the signaled algorithm or selects an algorithm/method based on the signaled method or algorithm. The selection is based, for example, on availability of the algorithm/method at the decoder/post-processor and/or cost of implementation. The video stream may comprise, for example, downsampled multiplexed stereoscopic images and the selected algorithm may include any of upconversion and/or error correction techniques that contribute to a restoration of the downsampled images.
    Type: Application
    Filed: September 13, 2022
    Publication date: January 5, 2023
    Applicant: DOLBY LABORATORIES LICENSING CORPORATION
    Inventors: Alexandros TOURAPIS, Athanasios LEONTARIS, Peshala V. PAHALAWATTA, Kevin J. STEC
  • Publication number: 20230005188
    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. The encoder is also configured to determine quantized minimum depths and/or maximum depths patch images in the image frames, wherein depth information is signaled relative to the quantized minimum depth.
    Type: Application
    Filed: August 26, 2022
    Publication date: January 5, 2023
    Applicant: Apple Inc.
    Inventors: Alexandros Tourapis, Fabrice A. Robinet, Jungsun Kim, Khaled Mammou, Valery G. Valentin, Yeping Su
  • Publication number: 20220417509
    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.
    Type: Application
    Filed: September 1, 2022
    Publication date: December 29, 2022
    Inventors: Alexandros Tourapis, Krishnakanth Rapaka, Dominik Mehlem
  • Patent number: 11539974
    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: Grant
    Filed: October 4, 2021
    Date of Patent: December 27, 2022
    Assignee: APPLE INC.
    Inventors: Alexandros Tourapis, Yeping Su, David Singer, Hsi-Jung Wu
  • Patent number: 11539959
    Abstract: Overlapped block disparity estimation and compensation is described. Compensating for images with overlapped block disparity compensation (OBDC) involves determining if OBDC is enabled in a video bit stream, and determining if OBDC is enabled for one or more macroblocks that neighbor a first macroblock within the video bit stream. The neighboring macroblocks may be transform coded. If OBDC is enabled in the video bit stream and for the one or more neighboring macroblocks, predictions may be made for a region of the first macroblock that has an edge adjacent with the neighboring macroblocks. OBDC can be causally applied. Disparity compensation parameters or modes may be shared amongst views or layers. A variety of predictions may be used with causally-applied OBDC.
    Type: Grant
    Filed: May 27, 2021
    Date of Patent: December 27, 2022
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Alexandros Tourapis, Athanasios Leontaris
  • Patent number: 11538196
    Abstract: An encoder is configured to compress point cloud geometry information using a prediction tree. Ancestor nodes of a node added to the prediction tree may be used to determine the predicted value of the node to be added according to a prediction technique. The prediction tree may be encoded and may be provided for transmission to a decoder that can regenerate the point cloud.
    Type: Grant
    Filed: October 1, 2020
    Date of Patent: December 27, 2022
    Assignee: Apple Inc.
    Inventors: Khaled Mammou, David Flynn, Alexandros Tourapis
  • Publication number: 20220408096
    Abstract: A video encoding and decoding system that implements an adaptive transfer function method internally within the codec for signal representation. A focus dynamic range representing an effective dynamic range of the human visual system may be dynamically determined for each scene, sequence, frame, or region of input video. The video data may be cropped and quantized into the bit depth of the codec according to a transfer function for encoding within the codec. The transfer function may be the same as the transfer function of the input video data or may be a transfer function internal to the codec. The encoded video data may be decoded and expanded into the dynamic range of display(s). The adaptive transfer function method enables the codec to use fewer bits for the internal representation of the signal while still representing the entire dynamic range of the signal in output.
    Type: Application
    Filed: August 26, 2022
    Publication date: December 22, 2022
    Inventors: Alexandros Tourapis, David Singer
  • Publication number: 20220405533
    Abstract: A search space for performing nearest neighbor searches for encoding point cloud data may be trimmed. Ranges of a space filling curve may be used to identify search space to exclude or reuse, instead of generating nearest neighbor search results for at least some of the points of a point cloud located within some of the ranges of the space filling curve. Additionally, neighboring voxels may be searched to identify any neighboring points missed during the trimmed search based on the ranges of the space filling curve.
    Type: Application
    Filed: August 5, 2022
    Publication date: December 22, 2022
    Applicant: Apple Inc.
    Inventors: Khaled Mammou, Alexandros Tourapis, David Flynn, Zhenzhen Gao
  • Patent number: 11533494
    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. The encoder generates an occupancy map and may also encode the occupancy map as an image based representation. In some embodiments, a video encoder encodes image based representations of spatial information for the points of the point cloud, image based representations of attribute values for points of the point cloud, and an image based representation of an occupancy map for the spatial and attribute images.
    Type: Grant
    Filed: February 26, 2021
    Date of Patent: December 20, 2022
    Assignee: Apple Inc.
    Inventors: Khaled Mammou, Valery G. Valentin, Fabrice A. Robinet, Alexandros Tourapis, Yeping Su, Jungsun Kim
  • Patent number: 11527018
    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.
    Type: Grant
    Filed: January 25, 2021
    Date of Patent: December 13, 2022
    Assignee: Apple Inc.
    Inventors: Khaled Mammou, Fabrice A. Robinet, Alexandros Tourapis, Yeping Su
  • Patent number: 11514611
    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 closed-loop color conversion process is used to improve compression while taking into consideration distortion introduced throughout the point cloud compression process.
    Type: Grant
    Filed: December 11, 2020
    Date of Patent: November 29, 2022
    Assignee: Apple Inc.
    Inventors: Khaled Mammou, Yeping Su, David W. Singer, Alexandros Tourapis, Fabrice A. Robinet, Hsi-Jung Wu
  • Patent number: 11508094
    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. In some embodiments, an encoder may be configured to further compress points omitted from the image based representation. Also, in some embodiments, a decoder may be configured to decode points compressed outside of an image based representation or in a separate image based representation.
    Type: Grant
    Filed: January 29, 2021
    Date of Patent: November 22, 2022
    Assignee: Apple Inc.
    Inventors: Khaled Mammou, Valery G. Valentin, Fabrice A. Robinet, Alexandros Tourapis, Yeping Su, Jungsun Kim