US-12620136-B2 - Method for decoding immersive video and method for encoding immersive video

US12620136B2US 12620136 B2US12620136 B2US 12620136B2US-12620136-B2

Abstract

A method of processing an immersive video according to the present disclosure includes performing pruning for an input image, generating an atlas based on patches generated by the pruning and generating a cropped atlas by removing a background region of the atlas.

Inventors

Kwan Jung Oh
Gwang Soon Lee
Jeong Il Seo
Hong Chang SHIN
Jun Young JEONG
Euee Seon Jang
Tian Yu DONG
Xin Li
Jai Young OH

Assignees

ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
IUCF-HYU (INDUSTRY-UNIVERSITY COOPERATION FOUNDATION HANYANG UNIVERSITY)

Dates

Publication Date: 20260505
Application Date: 20230112
Priority Date: 20220112

Claims (11)

1 . A method of encoding an immersive video, the method comprising: performing pruning for input images; generating an atlas by packing a plurality of patches generated by the pruning; and generating a cropped atlas from the atlas, wherein the cropped atlas is generated by removing from the atlas, a background region in which none of the patches are packed, wherein the cropped atlas is encoded instead of the atlas, wherein metadata for the cropped atlas is further encoded as well as the cropped atlas, and wherein the metadata comprises information representing whether the cropped atlas is encoded instead of the atlas.
2 . The method according to claim 1 , wherein in response that the information is encoded to indicate that the cropped atlas is encoded instead of the atlas, the metadata further comprises position information of the cropped atlas in the atlas and size information of the cropped atlas.
3 . The method according to claim 2 , wherein the position information comprises horizontal position information representing a position of a left boundary of the cropped atlas in the atlas and vertical position information representing a position of a top boundary of the cropped atlas in the atlas.
4 . The method according to claim 2 , wherein the size information includes width information of the cropped atlas and height information of the cropped atlas.
5 . The method according to claim 1 , wherein whether to generate the cropped atlas is determined based on whether object-based coding is applied, and wherein in response to the object-based coding being applied, only the patches derived from a first object are packed into the atlas while patches derived from objects other than the first object are excluded.
6 . The method according to claim 1 , wherein based on at least one of a size of the background region in the atlas or an attribute of an object from which the patches are derived, whether to generate the cropped atlas is determined.
7 . A method of decoding an immersive video, the method comprising: decoding an object map and either an atlas or a cropped atlas from a bitstream; and synthesizing a view image for a predetermined object based on the object map and either the atlas or the cropped atlas, wherein the atlas is divided into a data region and a background region, the data region being composed of a plurality of patches, the background region being a region in which none of patches are packed, wherein the cropped atlas comprises only the data region excluding the background region, wherein metadata for the cropped atlas is further decoded from the bitstream, and wherein the metadata comprises information representing whether the cropped atlas is decoded instead of the atlas.
8 . The method according to claim 7 , wherein in response that the information indicates that the cropped atlas is decoded instead of the atlas, the metadata further comprises position information of the cropped atlas in the atlas and size information of the cropped atlas.
9 . The method according to claim 8 , wherein the position information comprises horizontal position information representing a position of a left boundary of the cropped atlas in the atlas in an original size and vertical position information representing a position of a top boundary of the cropped atlas in the atlas in the original size.
10 . The method according to claim 8 , wherein the size information includes width information of the cropped atlas and height information of the cropped atlas.
11 . The method according to claim 7 , wherein in response to object-based coding being applied, encoding the cropped atlas is decoded instead of the atlas, and wherein in response to the object-based coding being applied, only patches derived from a first object are present in the atlas while patches derived from objects other than the first object are excluded.

Description

FIELD OF INVENTION The present disclosure relates to a method for encoding/decoding an immersive video which supports motion parallax for a rotation and translation motion. BACKGROUND OF THE INVENTION A virtual reality service is evolving in a direction of providing a service in which a sense of immersion and realism are maximized by generating an omnidirectional image in a form of an actual image or CG (Computer Graphics) and playing it on HMD, a smartphone, etc. Currently, it is known that 6 Degrees of Freedom (DoF) should be supported to play a natural and immersive omnidirectional image through HMD. For a 6DoF image, an image which is free in six directions including (1) left and right rotation, (2) top and bottom rotation, (3) left and right movement, (4) top and bottom movement, etc. should be provided through a HMD screen. But, most of the omnidirectional images based on an actual image support only rotary motion. Accordingly, a study on a field such as acquisition, reproduction technology, etc. of a 6DoF omnidirectional image is actively under way. DISCLOSURE Technical Problem The present disclosure is to provide a method of cropping a part of an atlas. The present disclosure is to provide a new information element related to a cropped atlas. The technical objects to be achieved by the present disclosure are not limited to the above-described technical objects, and other technical objects which are not described herein will be clearly understood by those skilled in the pertinent art from the following description. Technical Solution A method of encoding an immersive video according to the present disclosure includes performing pruning for an input image, generating an atlas based on patches generated by the pruning and generating a cropped atlas by removing a background region of the atlas. A method of decoding an immersive video according to the present disclosure includes decoding an atlas and an object map from a bitstream and synthesizing a view image for a predetermined object based on the atlas and the object map. In this case, the atlas may be a cropped atlas that a background region is removed. Technical Effects According to the present disclosure, encoding/decoding efficiency may be improved by encoding/decoding a cropped atlas instead of an atlas. According to the present disclosure, encoding/decoding efficiency may be improved by providing an information element related to a cropped atlas. Effects achievable by the present disclosure are not limited to the above-described effects, and other effects which are not described herein may be clearly understood by those skilled in the pertinent art from the following description. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a block diagram of an immersive video processing device according to an embodiment of the present disclosure. FIG. 2 is a block diagram of an immersive video output device according to an embodiment of the present disclosure. FIG. 3 is a flow chart of an immersive video processing method. FIG. 4 is a flow chart of an atlas encoding process. FIG. 5 is a flow chart of an immersive video output method. FIG. 6 is a flow chart of an immersive video processing method supporting object-based coding. FIG. 7 is a flow chart of an immersive video synthesis method supporting object-based coding. FIG. 8 is a flow chart of an immersive video processing method in which a function of cropping a part of an atlas is added to an immersive video processing method in FIG. 6. FIG. 9 represents an example in which a cropped atlas is generated. FIGS. 10 and 11 compare a performance change before and after a method of generating a cropped atlas proposed in the present disclosure is applied for a predetermined test sequence. DETAILED EMBODIMENTS As the present disclosure may make various changes and have multiple embodiments, specific embodiments are illustrated in a drawing and are described in detail in a detailed description. But, it is not to limit the present disclosure to a specific embodiment, and should be understood as including all changes, equivalents and substitutes included in an idea and a technical scope of the present disclosure. A similar reference numeral in a drawing refers to a like or similar function across multiple aspects. A shape and a size, etc. of elements in a drawing may be exaggerated for a clearer description. A detailed description on exemplary embodiments described below refers to an accompanying drawing which shows a specific embodiment as an example. These embodiments are described in detail so that those skilled in the pertinent art can implement an embodiment. It should be understood that a variety of embodiments are different each other, but they do not need to be mutually exclusive. For example, a specific shape, structure and characteristic described herein may be implemented in other embodiment without departing from a scope and a spirit of the present disclosure in connection with an embodiment. In addition, it sh