EP-4738831-A1 - IMAGE ENCODING/DECODING METHOD, METHOD FOR TRANSMITTING BITSTREAM, AND RECORDING MEDIUM HAVING STORED BITSTREAM THEREIN

Abstract

Provided are an image encoding/decoding method, a bitstream transmission method, and a computer-readable recording medium storing a bitstream. The image decoding method according to the present disclosure comprises the steps of: acquiring post-filter-based output picture information for an input picture from a neural-network post-filter (NNPF)-related supplemental enhancement information (SEI) message; and on the basis of the output picture information, acquiring an output picture for the input picture, wherein the output picture information may include output picture output information which is information indicating whether or not the output picture for the input picture is output.

Inventors

• TAN, Hendry

Assignees

• LG Electronics Inc.

Dates

Publication Date

20260506

Application Date

20240627

Claims (13)

1. An image decoding method performed by an image decoding apparatus, the image decoding method comprising: obtaining post-filter-based output picture information for an input picture from a neural-network post-filter (NNPF) related supplemental enhancement information (SEI) message; and obtaining an output picture for the input picture based on the output picture information, wherein the output picture information includes output picture output information, which is information specifying whether the output picture for the input picture is output.
2. The image decoding method of claim 1, wherein a value of the output picture output information is determined based on whether the input picture is present.
3. The image decoding method of claim 2, wherein the value of the output picture output information is determined further based on output picture presence information, which is information specifying whether the output picture for the input picture is present.
4. The image decoding method of claim 3, wherein based on the input picture being not present and the output picture presence information specifying that the output picture is present, the output picture output information specifies that the output picture is not output.
5. The image decoding method of claim 4, wherein a number of output picture output information is determined to be a value within a specific range.
6. The image decoding method of claim 5, wherein the specific range is determined based on an index value of a specific input picture.
7. The image decoding method of claim 4, wherein a number of output picture output information is always determined to be a value greater than a specific value.
8. The image decoding method of claim 4, wherein output of the output picture for the input picture which is not present is excluded in a filtering process based on the NNPF.
9. The image decoding method of claim 3, wherein the output picture presence information is obtained from an NNPFC SEI message.
10. The image decoding method of claim 1, wherein the output picture output information is obtained from an NNPFA SEI message.
11. An image encoding method performed by an image encoding apparatus, the image encoding method comprising: determining post-filter-based output picture information for an input picture; and signaling the output picture information as a neural-network post-filter (NNPF) related supplemental enhancement information (SEI) message, wherein the output picture information includes output picture output information, which is information specifying whether an output picture for the input picture is output.
12. A computer-readable medium storing a bitstream generated by the image encoding method of claim 11.
13. A method of transmitting a bitstream generated by an image encoding method, the image encoding method comprising: determining post-filter-based output picture information for an input picture; and signaling the output picture information as a neural-network post-filter (NNPF) related supplemental enhancement information (SEI) message, wherein the output picture information includes output picture output information, which is information specifying whether an output picture for the input picture is output.

Description

Technical Field The present disclosure relates to an image encoding/decoding method, a method of transmitting a bitstream and a recording medium storing a bitstream, and more specifically, to an image encoding/decoding method related to a neural-network post-processing filter, a method of transmitting a bitstream and a recording medium storing a bitstream. Background Art Recently, demand for high-resolution and high-quality images such as high definition (HD) images and ultra high definition (UHD) images is increasing in various fields. As resolution and quality of image data are improved, the amount of transmitted information or bits relatively increases as compared to existing image data. An increase in the amount of transmitted information or bits causes an increase in transmission cost and storage cost. Accordingly, there is a need for high-efficient image compression technology for effectively transmitting, storing and reproducing information on high-resolution and high-quality images. Disclosure Technical Problem An object of the present disclosure is to provide an image encoding/decoding method and apparatus with improved encoding/decoding efficiency. Also, an object of the present disclosure is to provide a method of processing NNPF related SEI messages (NNPFC SEI and NNPFA SEI). Also, an object of the present disclosure is to more clearly specify an output picture of NNPF by the NNPF related SEI message. Also, an object of the present disclosure is to provide clarify the meaning of information related to the output picture of NNPF. Also, an object of the present disclosure is to reduce the error of a decoder by clarifying the meaning of information related to the output picture of NNPF. Also, an object of the present disclosure is to improve coding quality and efficiency by clarifying the meaning of information related to the output picture of NNPF. Also, an object of the present disclosure is to improve coding efficiency by determining whether to output an output picture when an input picture is not present. Also, an object of the present disclosure is to provide a non-transitory computer-readable recording medium storing a bitstream generated by an image encoding method according to the present disclosure. Also, an object of the present disclosure is to provide a non-transitory computer-readable recording medium storing a bitstream received, decoded and used to reconstruct an image by an image decoding apparatus according to the present disclosure. Also, an object of the present disclosure is to provide a method of transmitting a bitstream generated by an image encoding method according to the present disclosure. The technical problems solved by the present disclosure are not limited to the above technical problems and other technical problems which are not described herein will become apparent to those skilled in the art from the following description. Technical Solution An image decoding method performed by an image decoding apparatus according to an embodiment of the present disclosure may comprise obtaining post-filter-based output picture information for an input picture from a neural-network post-filter (NNPF) related supplemental enhancement information (SEI) message and obtaining an output picture for the input picture based on the output picture information. The output picture information may include output picture output information, which is information specifying whether the output picture for the input picture is output. Meanwhile, as an embodiment, a value of the output picture output information may be determined based on whether the input picture is present. Meanwhile, as an embodiment, a value of the output picture output information may be further determined based on output picture presence information, which is information specifying whether the output picture for the input picture is present. Meanwhile, as an embodiment, based on the input picture being not present and the output picture presence information specifying that the output picture is present, the output picture output information may specify that the output picture is not output. Meanwhile, as an embodiment, the number of output picture output information may be determined to be a value within a specific range. Meanwhile, as an embodiment, the specific range may be determined based on an index value of a specific input picture. Meanwhile, as an embodiment, the number of output picture output information may be always determined to be a value greater than a specific value. Meanwhile, as an embodiment, output of the output picture for the input picture which is not present may be excluded in a filtering process based on the NNPF. Meanwhile, as an embodiment, the output picture presence information may be obtained from an NNPFC SEI message. Meanwhile, as an embodiment, the output picture output information may be obtained from an NNPFA SEI message. An image encoding method performed by an image encoding apparatus acco