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: 20210312670
    Abstract: 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: Application
    Filed: April 7, 2021
    Publication date: October 7, 2021
    Inventors: Khaled Mammou, David Flynn, Alexandros Tourapis
  • Patent number: 11132818
    Abstract: Attributes for point cloud compression may be predicted according to a space filling curve. An order for selecting points of a point cloud to be compressed in order to predict attributes of the points may be determined according to values of a space filling curve applied to spatial information for the points. A point of the point cloud may be selected according to the determined ordering. A prediction technique may be performed with respect to the selected point based on a set of neighboring points in the point cloud also selected according to the ordering. Predicted attribute values and correction values may be determined for the predicted values. The correction values may be encoded as part of a compressed version of the point cloud.
    Type: Grant
    Filed: September 27, 2019
    Date of Patent: September 28, 2021
    Assignee: Apple Inc.
    Inventors: Khaled Mammou, Alexandros Tourapis, Jungsun Kim, Valery G. Valentin, Fabrice A. Robinet, Yeping Su
  • Publication number: 20210289210
    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: Application
    Filed: May 27, 2021
    Publication date: September 16, 2021
    Inventors: Alexandros Tourapis, Athanasios Leontaris
  • Patent number: 11113845
    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: September 17, 2018
    Date of Patent: September 7, 2021
    Assignee: Apple Inc.
    Inventors: Alexandros Tourapis, Khaled Mammou, Yeping Su, Fabrice A. Robinet, David W. Singer
  • Publication number: 20210266597
    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. 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, a bit stream structure may be used to communicate compressed point cloud data. The bit stream structure may include point cloud compression network abstraction layer (PCCNAL) units that enable use of groups of frames (GOFs), frame, and sub-frame signaling of patch information. Such a bit stream structure may permit low delay streaming and random access reconstruction of point clouds amongst other applications.
    Type: Application
    Filed: May 12, 2021
    Publication date: August 26, 2021
    Applicant: Apple Inc.
    Inventors: Jungsun Kim, Alexandros Tourapis, Khaled Mammou, Fabrice A. Robinet, Yeping Su, David W. Singer
  • Publication number: 20210264640
    Abstract: A system comprises an encoder configured to compress attribute information for a point cloud and/or a decoder configured to decompress compressed attribute for the point cloud. To compress the attribute information, attribute values are predicted using one of a plurality of prediction strategies, wherein a selected prediction strategy is selected based at least in part on attribute variability of points in a neighborhood of points. A decoder follows a similar prediction process. Also, attribute correction values may be determined to correct predicted attribute values and may be used by a decoder to decompress a point cloud, wherein the decoder applies the same prediction strategy applied at the encoder.
    Type: Application
    Filed: May 12, 2021
    Publication date: August 26, 2021
    Applicant: Apple Inc.
    Inventors: Khaled Mammou, Jungsun Kim, Valery G. Valentin, Fabrice A. Robinet, Yeping Su, Alexandros Tourapis
  • Publication number: 20210258617
    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. To compress the attribute information, multiple levels of detail are generated based on an ordering of the points according to a space filling curve and attribute values are predicted. The attribute values may be predicted simultaneously while points are being assigned to different levels of detail. A decoder follows a similar prediction process based on level of details. Also, attribute correction values may be determined to correct predicted attribute values and may be used by a decoder to decompress a point cloud compressed using level of detail attribute compression. In some embodiments, attribute correction values may take into account an influence factor of respective points in a given level of detail on attributes in other levels of detail.
    Type: Application
    Filed: January 29, 2021
    Publication date: August 19, 2021
    Applicant: Apple Inc.
    Inventors: Alexandros Tourapis, Jungsun Kim, Valery G. Valentin, Fabrice A. Robinet, Yeping Su, Khaled Mammou
  • Publication number: 20210256735
    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 processing/filtering element utilizes occupancy map information and/or auxiliary patch information to determine relationships between patches in image frames and adjusts encoding/decoding and/or filtering or pre/post-processing parameters based on the determined relationships.
    Type: Application
    Filed: May 3, 2021
    Publication date: August 19, 2021
    Applicant: Apple Inc.
    Inventors: Alexandros Tourapis, Khaled Mammou, Yeping Su, Jungsun Kim, Valery G. Valentin, David W. Singer, Fabrice A. Robinet, Hsi-Jung Wu
  • Publication number: 20210243455
    Abstract: A multi-stage coding method includes receiving an input block of data for encoding and one or more previously coded samples associated with the input block. The input block is segmented into at least a first sub-region and a second sub-region. A prediction for the first sub-region is generated based on the one or more previously coded samples. Residual data for the first sub-region is obtained using the prediction for the first sub-region. A reconstruction of the first sub-region is generated using the residual data for the first sub-region and the prediction for the first sub-region. A prediction for the second sub-region is generated using the reconstruction of the first sub-region. Residual data for the second sub-region is obtained using the prediction for the second sub-region. The input block is encoded based in part on the residual data for the first region and the residual data for the second region.
    Type: Application
    Filed: February 4, 2021
    Publication date: August 5, 2021
    Inventors: Krishnakanth Rapaka, Alexandros Tourapis, David William Singer
  • Publication number: 20210243451
    Abstract: Techniques are disclosed for 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: Application
    Filed: March 30, 2020
    Publication date: August 5, 2021
    Inventors: Mei Guo, Jun Xin, Hsi-Jung Wu, Alexandros Tourapis, Krishnakanth Rapaka
  • Publication number: 20210235088
    Abstract: 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: Application
    Filed: April 16, 2021
    Publication date: July 29, 2021
    Inventors: Alexandros Tourapis, Guy Cote
  • Publication number: 20210227236
    Abstract: Aspects of the present disclosure provide techniques for reducing latency and improving image quality of a viewport extracted from multi-directional video communications. According to such techniques, first streams of coded video data are received from a source. The first streams include coded data for each of a plurality of tiles representing a multi-directional video, where each tile corresponding to a predetermined spatial region of the multi-directional video, and at least one tile of the plurality of tiles in the first streams contains a current viewport location at a receiver. The techniques include decoding the first streams and displaying the tile containing the current viewport location. When the viewport location at the receiver changes to include a new tile of the plurality of tiles, retrieving and decoding first streams for the new tile, displaying the decoded content for the changed viewport location, and transmitting the changed viewport location to the source.
    Type: Application
    Filed: April 2, 2021
    Publication date: July 22, 2021
    Inventors: Alexandros Tourapis, Dazhong Zhang, Hang Yuan, Hsi-Jung Wu, Jae Hoon Kim, Jiefu Zhai, Ming Chen, Xiaosong Zhou
  • Publication number: 20210217203
    Abstract: 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: Application
    Filed: January 8, 2021
    Publication date: July 15, 2021
    Applicant: Apple Inc.
    Inventors: Jungsun Kim, Khaled Mammou, Alexandros Tourapis
  • Publication number: 20210211683
    Abstract: System and method for improving video encoding and/or video decoding. In embodiments, a video encoding pipeline includes a main encoding pipeline that compresses source image data corresponding with an image frame by processing the source image data based at least in part on encoding parameters to generate encoded image data. Additionally the video encoding pipeline includes a machine learning block communicatively coupled to the main encoding pipeline, in which the machine learning block analyzes content of the image frame by processing the source image data based at least in part on machine learning parameters implemented in the machine learning block when the machine learning block is enabled by the encoding parameters; and the video encoding pipeline adaptively adjusts the encoding parameters based at least in part on the content expected to be present in the image frame to facilitate improving encoding efficiency.
    Type: Application
    Filed: March 23, 2021
    Publication date: July 8, 2021
    Inventors: Jim C. Chou, Alexandros Tourapis
  • Publication number: 20210211724
    Abstract: A system comprises an encoder configured to compress attribute information and/or spatial information for volumetric visual content and/or a decoder configured to decompress compressed attribute and/or spatial information for the volumetric visual content. The encoder is configured to convert a 3D representation of the visual volumetric content into a 2D image based representation. The encoder is further configured to scale the patch in 2D space independent of any scaling in 3D space. Auxiliary information is signaled for use in identifying 2D scaled or unscaled patches in an image frame, mapping the patches into 3D space, and adjusting for any scaling factors applied at the encoder.
    Type: Application
    Filed: January 8, 2021
    Publication date: July 8, 2021
    Applicant: Apple Inc.
    Inventors: Jungsun Kim, Khaled Mammou, Alexandros Tourapis
  • Publication number: 20210211703
    Abstract: In an example method, points that represent three-dimensional visual volumetric content are received, and patches are determined, where each patch corresponds to a respective portion of the visual volumetric content. A patch image representing a set of points corresponding to the patch projected onto a respective patch plane is generated for each patch. The patch images are packed into image frames, and the image frames are encoded. An occupancy map corresponding to the image frames is generated. The occupancy map indicates, for each image frame: locations of the patch images in the image frame, and depth information of sets of points corresponding to the patch images in the image frame. The depth information indicates, for each patch image, depths of the set of points corresponding to the patch image in a direction perpendicular to a patch plane of the patch image.
    Type: Application
    Filed: January 7, 2021
    Publication date: July 8, 2021
    Inventors: Jungsun Kim, Alexandros Tourapis, Khaled Mammou
  • Publication number: 20210195246
    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 recreates 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: December 18, 2020
    Publication date: June 24, 2021
    Inventors: Alexandros Tourapis, Hye-Yeon Cheong, David William Singer, Dominik Mehlem
  • Patent number: 11044478
    Abstract: A system comprises an encoder configured to compress images, such as image frames comprising attribute information and/or spatial for a point cloud and/or an occupancy map for the point cloud. Also, a system includes a decoder configured to decompress compressed image frames, such as image frames comprising compressed attribute and/or spatial information for the point cloud or an occupancy map for the point cloud. Additionally, the encoder may map N-bit data to M-bit code words, where M is less than N. Alternatively the encoder may map N-bit data to M-bit code words, where M is greater than N. In a similar manner, a decoder may map the M-bit code words back to the N-bit data.
    Type: Grant
    Filed: July 1, 2019
    Date of Patent: June 22, 2021
    Assignee: Apple Inc.
    Inventors: Alexandros Tourapis, Jungsun Kim, Fabrice A. Robinet, Khaled Mammou, Valery G. Valentin, Yeping Su
  • Publication number: 20210185361
    Abstract: In communication applications, aggregate source image data at a transmitter exceeds the data that is needed to display a rendering of a viewport at a receiver. Improved streaming techniques that include estimating a location of a viewport at a future time. According to such techniques, the viewport may represent a portion of an image from a multi-directional video to be displayed at the future time, and tile(s) of the image may be identified in which the viewport is estimated to be located. In these techniques, the image data of tile(s) in which the viewport is estimated to be located may be requested at a first service tier, and the other tile in which the viewport is not estimated to be located may be requested at a second service tier, lower than the first service tier.
    Type: Application
    Filed: March 1, 2021
    Publication date: June 17, 2021
    Inventors: Xiaohua YANG, Alexandros TOURAPIS, Dazhong ZHANG, Hang YUAN, Hsi-Jung WU, Jae Hoon KIM, Jiefu ZHAI, Ming CHEN, Xiaosong ZHOU
  • Publication number: 20210185331
    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: Application
    Filed: February 26, 2021
    Publication date: June 17, 2021
    Applicant: Apple Inc.
    Inventors: Khaled Mammou, Valery G. Valentin, Fabrice A. Robinet, Alexandros Tourapis, Yeping Su, Jungsun Kim