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).
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Patent number: 11887345Abstract: A system receives encoded data regarding a points in a point cloud. The data includes a prediction tree having a nodes generated based on spatial information regarding the points and properties of a sensor system that obtained the spatial information. A value of each node represents first spatial coordinates of a respective one of the points according to a first coordinate system, and the value of at least a first node in the prediction tree is determined based on ancestor nodes of the first node and the properties of the sensor system. The system decodes the data to determine first data, including the first spatial coordinates of at least some of the points, and quantization parameters associated with the first spatial coordinates. The system determines second data based on the first data, including second spatial coordinates of at least some of the points according to a second coordinate system.Type: GrantFiled: April 7, 2021Date of Patent: January 30, 2024Assignee: Apple Inc.Inventors: Khaled Mammou, David Flynn, Alexandros Tourapis
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Publication number: 20240022765Abstract: A system comprises an encoder configured to compress and encode data for a three-dimensional mesh. To compress the three-dimensional mesh, the encoder determines a compressed base mesh bit stream and a compressed motion bitstream. A network abstraction layer syntax defined for the compressed base mesh bit stream and the compressed motion bitstream, allows for various parameters to be defined and applied to both bit streams, such as timing information and faceIDs for faces of polygons of the mesh.Type: ApplicationFiled: July 14, 2023Publication date: January 18, 2024Applicant: Apple Inc.Inventors: Alexandros Tourapis, Dimitri Podborski, Jungsun Kim, Khaled Mammou
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Patent number: 11863738Abstract: 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: GrantFiled: December 2, 2021Date of Patent: January 2, 2024Assignee: APPLE INC.Inventors: Alexandros Tourapis, Jungsun Kim, Krishnakanth Rapaka, David W. Singer
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Publication number: 20230421812Abstract: 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: ApplicationFiled: September 14, 2023Publication date: December 28, 2023Applicant: DOLBY LABORATORIES LICENSING CORPORATIONInventors: Alexandros TOURAPIS, Athanasios LEONTARIS, Peshala V. PAHALAWATTA, Kevin J. STEC
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Publication number: 20230421813Abstract: 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: ApplicationFiled: September 14, 2023Publication date: December 28, 2023Applicant: DOLBY LABORATORIES LICENSING CORPORATIONInventors: Alexandros TOURAPIS, Athanasios LEONTARIS, Peshala V. PAHALAWATTA, Kevin J. STEC
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Publication number: 20230421811Abstract: 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: ApplicationFiled: September 14, 2023Publication date: December 28, 2023Applicant: DOLBY LABORATORIES LICENSING CORPORATIONInventors: Alexandros TOURAPIS, Athanasios LEONTARIS, Peshala V. PAHALAWATTA, Kevin J. STEC
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Patent number: 11854112Abstract: A system compresses and decompresses attribute information for visual volumetric content, such as a mesh representation. Attribute values are included in the visual volumetric representation, wherein at least some of the attribute values include unitary vectors, such as surface normal vectors or surface tangent vectors having a magnitude of one unit. In order to compress the attribute information the three-dimensional unit vectors are mapped into two dimensional parametric coordinates for a planar representation of a unit sphere. To reduce negative effects on compression due to distortion or discontinuities in the planar representation, mappings for compressing respective unit vectors are adaptively selected.Type: GrantFiled: May 17, 2022Date of Patent: December 26, 2023Assignee: Apple Inc.Inventors: Khaled Mammou, Deepak S Tolani, Alexandros Tourapis
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Publication number: 20230403396Abstract: A method of signaling additional chroma QP offset values that are specific to quantization groups is provided, in which each quantization group explicitly specifies its own set of chroma QP offset values. Alternatively, a table of possible sets of chroma QP offset values is specified in the header area of the picture, and each quantization group uses an index to select an entry from the table for determining its own set of chroma QP offset values. The quantization group specific chroma QP offset values are then used to determine the chroma QP values for blocks within the quantization group in addition to chroma QP offset values already specified for higher levels of the video coding hierarchy.Type: ApplicationFiled: August 29, 2023Publication date: December 14, 2023Inventors: Alexandros Tourapis, Guy Cote
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Publication number: 20230401751Abstract: 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: ApplicationFiled: August 18, 2023Publication date: December 14, 2023Applicant: Apple Inc.Inventors: Khaled Mammou, Alexandros Tourapis, Jungsun Kim
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Publication number: 20230401755Abstract: A system comprises an encoder configured to compress and encode data for a three-dimensional mesh. To compress the three-dimensional mesh, the encoder determines sub-meshes and for each sub-mesh: texture patches and geometry patches. Also, the sub-meshes may be grouped into patches, patch-groups, and/or tiles. Different encoding parameters may be used for such different coding units (e.g., patches, patch-groups and/or tiles). However, the encoding parameters are adjusted for vertices that are shared between coding units to avoid introduction of artefacts. A decoder receives a bit stream as generated by the encoder and reconstructs the three-dimensional mesh.Type: ApplicationFiled: April 19, 2023Publication date: December 14, 2023Applicant: Apple Inc.Inventors: Khaled Mammou, Alexandros Tourapis, Jungsun Kim, Dimitri Podborski
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Patent number: 11843783Abstract: 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: GrantFiled: December 15, 2022Date of Patent: December 12, 2023Assignee: DOLBY LABORATORIES LICENSING CORPORATIONInventors: Alexandros Tourapis, Athanasios Leontaris
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Publication number: 20230388514Abstract: 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: ApplicationFiled: August 15, 2023Publication date: November 30, 2023Inventors: Alexandros Tourapis, Athanasios Leontaris
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Publication number: 20230370598Abstract: A method of signaling additional chroma QP offset values that are specific to quantization groups is provided, in which each quantization group explicitly specifies its own set of chroma QP offset values. Alternatively, a table of possible sets of chroma QP offset values is specified in the header area of the picture, and each quantization group uses an index to select an entry from the table for determining its own set of chroma QP offset values. The quantization group specific chroma QP offset values are then used to determine the chroma QP values for blocks within the quantization group in addition to chroma QP offset values already specified for higher levels of the video coding hierarchy.Type: ApplicationFiled: April 20, 2023Publication date: November 16, 2023Inventors: Alexandros Tourapis, Guy Cote
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Patent number: 11818401Abstract: 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: GrantFiled: April 12, 2022Date of Patent: November 14, 2023Assignee: Apple Inc.Inventors: Alexandros Tourapis, Jungsun Kim, Valery G. Valentin, Fabrice A. Robinet, Yeping Su, Khaled Mammou
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Patent number: 11798196Abstract: A system comprises an encoder configured to compress attribute information and/or spatial information for three-dimensional (3D) visual volumetric content and/or a decoder configured to decompress compressed attribute and/or spatial information for the 3D visual volumetric content. The encoder is configured to convert 3D visual volumetric content, such as a point cloud or mesh, into image based patch representations. The encoder is further configured to select one or more reference patches for copying or prediction, such that metadata for copying or predicting a patch based on the reference patch is signaled without explicitly signaling a full set of information for the copied or predicted patch. Likewise, a decoder is configured to receive such information and reconstruct a 3D version of the 3D visual volumetric content using both signaled and predicted or copied patches.Type: GrantFiled: January 8, 2021Date of Patent: October 24, 2023Assignee: Apple Inc.Inventors: Jungsun Kim, Khaled Mammou, Alexandros Tourapis
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Patent number: 11792428Abstract: 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: GrantFiled: February 27, 2023Date of Patent: October 17, 2023Assignee: DOLBY LABORATORIES LICENSING CORPORATIONInventors: Alexandros Tourapis, Athanasios Leontaris, Peshala V. Pahalawatta, Kevin J. Stec
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Patent number: 11792429Abstract: 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: GrantFiled: February 27, 2023Date of Patent: October 17, 2023Assignee: DOLBY LABORATORIES LICENSING CORPORATIONInventors: Alexandros Tourapis, Athanasios Leontaris, Peshala V. Pahalawatta, Kevin J. Stec
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Patent number: 11783508Abstract: 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: GrantFiled: September 16, 2022Date of Patent: October 10, 2023Assignee: Apple Inc.Inventors: Khaled Mammou, Alexandros Tourapis, Jungsun Kim
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Publication number: 20230319310Abstract: 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. Additionally, an encoder is configured to signal and/or a decoder is configured to receive a supplementary message comprising volumetric tiling information that maps portions of 2D image representations to objects in the point. In some embodiments, characteristics of the object may additionally be signaled using the supplementary message or additional supplementary messages.Type: ApplicationFiled: June 5, 2023Publication date: October 5, 2023Applicant: Apple Inc.Inventors: Alexandros Tourapis, Jungsun Kim, Khaled Mammou, David W. Singer, Fabrice A. Robinet
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Publication number: 20230316655Abstract: A three-dimensional (3D) mesh encoder is provided. The 3D mesh encoder can include a preprocessing stage configured to generate the mesh M by re-sampling the mesh M and computing a new atlas of parametrization with a fewer number of patches and relatively lower parameterization distortion. The 3D mesh encoder may include an attribute transfer stage for transferring attributes to the re-sampled mesh M.Type: ApplicationFiled: February 8, 2023Publication date: October 5, 2023Inventors: Khaled Mammou, Alexandros Tourapis, Jungsun Kim