RU-2861289-C2 - SIGNALLING OF OUTPUT IMAGE SIZE FOR REFERENCE IMAGE RESAMPLING

Abstract

FIELD: computing technology. SUBSTANCE: invention relates to means for video encoding. Video data is obtained. It is determined whether a metadata component of this video data should contain at least one flag signalling at least one image size component for at least one image of the video data. In response to determining that the metadata component should contain said at least one flag and based on metadata determined to indicate the width and/or height for a plurality of images, it is determined whether any subsequent resampling process should be applied to each of the plurality of cropped output images, so that each of the plurality of resampled output images has a constant image size. Encoding of the video data and signalling syntax into a video data bitstream is performed. EFFECT: increasing video encoding efficiency. 11 cl, 13 dwg

Inventors

• CHOI BYEONGDOO
• WENGER STEPHAN
• LIU SHAN

Dates

Publication Date

20260504

Application Date

20201109

Priority Date

20201005

Claims (20)

1. 1. A method for encoding video data, comprising:
2. receiving video data;
3. determining whether a metadata component of the video data is to contain at least one flag signaling at least one image size component for at least one image of the video data;
4. in response to determining that the metadata component is to contain said at least one flag and based on metadata defined to indicate a width and/or height for a plurality of images, determining whether any subsequent resampling process is to be applied to each of the plurality of cropped output images such that each of the plurality of resampled output images has a constant image size; and
5. encoding video data and signaling syntax into a video data bitstream.
6. 2. The method according to claim 1, wherein the video data has a universal video coding (VVC) format.
7. 3. The method of claim 1, wherein said image size component for the at least one image includes at least one dimension of said at least one image.
8. 4. The method according to claim 3, wherein said at least one dimension of said at least one image is represented in units of brightness readings.
9. 5. The method according to any one of paragraphs 1-4, in which said at least one flag indicates whether to display said at least one image with an image size in accordance with the value of a component that is present and indicated by the metadata.
10. 6. The method according to any one of paragraphs 1-5, in which any said subsequent resampling process is applied to the cropped output images.
11. 7. The method according to any one of claims 1 to 6, wherein the subsequent resampling process is a reference picture resampling (RPR), and said syntax signals whether RPR is applied based on whether a cropping parameter, which is indicated by said at least one flag, is included in the set of sequence parameters or is to be determined from the set of sequence parameters, wherein the cropping parameter represents a constant width and/or height of the output RPR image in units of luminance samples.
12. 8. The method according to any one of paragraphs 1-7, in which:
13. the mentioned syntax signals that any subsequent resampling process mentioned must maintain the width value equal to the value specified by the video data sequence parameter set.
14. 9. The method according to any one of paragraphs 1-7, in which:
15. the mentioned syntax signals that any subsequent resampling process mentioned must maintain the height value equal to the value specified by the video data sequence parameter set.
16. 10. The method according to any one of paragraphs 1-9, in which:
17. said at least one flag represents a video usage information (VUI) parameter.
18. 11. A device for encoding video data, comprising:
19. at least one memory configured to store computer program code; and
20. at least one processor configured to access the computer program code and operate in accordance with the instructions of the computer program code to implement the method according to any one of claims 1-10.

Description

CROSS-REFERENCE TO A RELATED APPLICATION [1] This application claims priority to U.S. Provisional Patent Application No. 62/955,514, filed December 31, 2019, and U.S. Provisional Patent Application No. 17/063,253, filed October 5, 2020, which are incorporated herein in their entirety. PREREQUISITES FOR THE CREATION OF THE INVENTION 1. Field of technology [2] The present invention is directed to signaling constant image size information, such as in video usage information (VUI), wherein, according to exemplary embodiments of the invention, such information may indicate, among other information described herein, a controlled output image size for display, with or without one or more cropped output images that have any of one or more different width and height values for processing such as reference picture resampling (RPR). 2. State of the art [3] In the draft specification for universal video coding (VVC) JVET-P2001 (new edition of JVET-Q0041), the RPR may allow for changing one or more spatial resolutions of the decoded image. Depending on the image width and height and the crop window offset values signaled in the picture parameter set (PPS), each output image may have an image size different from the size of other output images. However, the drawback of this solution is the requirement that the display device, for example as a post-processing step, be able to rescale the output images to a constant image size to match the display resolution of the display device. [4] Such post-processing was previously assigned to each display device and, therefore, limited the technical capabilities for controlling the pre-processing of image output on the display device, such as the ability to control the display device's display resolution. For example, in some content delivery scenarios, the content provider, due to technical limitations, was unable to provide the consumed video content or at least output the video content at a certain resolution and could not even specify the best or recommended resolution for display, in accordance with, for example, the director's intent. [5] Furthermore, even the JVET-N0052 abandoned the signaling of the (constant) output image size in the SPS in order to leave a process or processes such as post-processing outside the decoding process. [6] Therefore, there is a need for a technical solution to such problems. ESSENCE OF THE INVENTION [7] To satisfy one or more different requirements that reflect, for example, the director's intent and leave the display freedom for post-processing, the inventors propose technical solutions that include signaling any constant output image size in the VUI, for example, in the form of informative metadata. According to embodiments of the invention, the end user device can still select the resolution of the displayed image and can also optionally accept the director's suggestion. [8] A method and apparatus are provided, comprising a memory configured to store a computer program code, and a processor or processors configured to access the computer program code and operate in accordance with the instructions of the computer program code. The computer program code includes an acquisition code configured to ensure that at least one processor receives an input bit stream containing metadata and video data, a decoding code configured to ensure that at least one processor decodes the video data, a determination code configured to ensure that at least one processor determines whether the metadata contains at least one flag signaling at least one image size component for at least one image of the video data, and a signaling code configured to ensure that at least one processor transmits a signal, if it is determined that the metadata contains the at least one flag, to a display device for displaying at least one image from the video data in accordance with the at least one flag. [9] According to embodiments of the invention, the video data is encoded in the universal video coding (VVC) format. [10] According to embodiments of the invention, said at least one flag indicates whether said at least one image should be displayed with an image size in accordance with the value of said component, which is pre-set and indicated by means of metadata. [11] According to embodiments of the invention, said component includes the width and/or height of said at least one image. [12] According to embodiments of the invention, the width and/or height of said at least one image is represented in units of brightness readings. [13] According to exemplary embodiments of the invention, the determining code is also configured to cause at least one processor, in response to determining that the metadata contains said at least one flag, to determine whether the metadata contains a width value that defines a width with respect to a plurality of images that includes said at least one image, and whether the metadata contains a height value that defines a height with respect to a plurality