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US 11,539,882 B2Granted
Method and apparatus for reconstructing 360-degree image according to projection format
AssigneeB1 Institute of Image Technology, Inc.
InventorKi Baek Kim
Life of this patent
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Abstract
Disclosed are methods and apparatuses for image data encoding/decoding. A method for decoding a 360-degree image includes the steps of: receiving a bitstream obtained by encoding a 360-degree image; generating a prediction image by making reference to syntax information obtained from the received bitstream; adding the generated prediction image to a residual image obtained by dequantizing and inverse-transforming the bitstream, so as to obtain a decoded image; and reconstructing the decoded image into a 360-degree image according to a projection format. Therefore, the performance of image data compression can be improved.
Claims10
A method for decoding a 360-degree image, the method comprising:
- receiving a bitstream in which the 360-degree image is encoded, the bitstream including data of an extended 2-dimensional image, the extended 2-dimensional image including a 2-dimensional image and a predetermined extension region, and the 2-dimensional image being from an image with a 3-dimensional projection structure and including one or more faces;
- generating a prediction image by referring to syntax information obtained from the received bitstream;
- obtaining a decoded image by adding the generated prediction image to a residual image, the residual image being obtained by inverse-quantizing and inverse transforming quantized transform coefficients, the quantized transform coefficients being obtained by performing entropy-decoding or variable-length-decoding for residual information included in the bitstream;
- and
- reconstructing the decoded image into the 360-degree image according to a projection format,
- wherein the projection format is selectively determined based on identification information, among a plurality of pre-defined projection formats including an ERP format in which the 360-degree image is projected in a two-dimensional plane or a CMP format in which the 360-degree image is projected in a cube,
- wherein a size of the extension region is variably determined based on at least one of first information indicating a width of the extension region or second information indicating a height of the extension region, independently of a size of the 2-dimensional image,
- wherein the extension region is not included in the image with the 3-dimensional projection structure, and
- wherein at least one of the identification information, the first information or the second information is obtained from the bitstream.
6 more elements
A method for encoding a 360-degree image, the method comprising:
- generating a bitstream in which the 360-degree image is encoded, the bitstream including data of an extended 2-dimensional image, the extended 2-dimensional image including a 2-dimensional image and a predetermined extension region, and the 2-dimensional image being from an image with a 3-dimensional projection structure and including one or more faces;
- wherein the bitstream comprises syntax information, the syntax information being referred to for generating a prediction image,
- the bitstream comprises residual information, the residual information being entropy-decoded or variable-length-decoded for obtaining quantized transform coefficients, the quantized transform coefficients being inverse-quantized and inverse transformed for obtaining a residual image,
- the prediction image is added to the residual image for obtaining a decoded image, and
- the decoded image is reconstructed into the 360-degree image according to a projection format,
- wherein the projection format is selectively determined based on identification information, among a plurality of pre-defined projection formats including an ERP format in which the 360-degree image is projected in a two-dimensional plane or a CMP format in which the 360-degree image is projected in a cube,
- wherein a size of the extension region is variably determined based on at least one of first information indicating a width of the extension region or second information indicating a height of the extension region, independently of a size of the 2-dimensional image,
- wherein the extension region is not included in the image with the 3-dimensional projection structure, and
- wherein at least one of the identification information, the first information or the second information is encoded into the bitstream.
6 more elements
A method for transmitting a bitstream, the method comprising:
- transmitting the bitstream to an image decoding apparatus,
- wherein the bitstream is generated by encoding the 360-degree image, the bitstream including data of an extended 2-dimensional image, the extended 2-dimensional image including a 2-dimensional image and a predetermined extension region, and the 2-dimensional image being from an image with a 3-dimensional projection structure and including one or more faces;
- wherein the bitstream comprises syntax information, the syntax information being referred to for generating a prediction image,
- the bitstream comprises residual information, the residual information being entropy-decoded or variable-length-decoded for obtaining quantized transform coefficients, the quantized transform coefficients being inverse-quantized and inverse transformed for obtaining a residual image,
- the prediction image is added to the residual image for obtaining a decoded image, and
- the decoded image is reconstructed into the 360-degree image according to a projection format,
- wherein the projection format is selectively determined based on identification information, among a plurality of pre-defined projection formats including an ERP format in which the 360-degree image is projected in a two-dimensional plane or a CMP format in which the 360-degree image is projected in a cube,
- wherein a size of the extension region is variably determined based on at least one of first information indicating a width of the extension region or second information indicating a height of the extension region, independently of a size of the 2-dimensional image,
- wherein the extension region is not included in the image with the 3-dimensional projection structure, and
- wherein at least one of the identification information, the first information or the second information is encoded into the bitstream.
7 more elements
Dependencies are inferred from the claim text.