KR-20260067353-A - VIDEO CODING METHOD AND APPARATUS, AND RECORDING MEDIUM STORING BITSTREAM

KR20260067353AKR 20260067353 AKR20260067353 AKR 20260067353AKR-20260067353-A

Abstract

A video signal decoding method and apparatus according to the present disclosure may include: a step of generating a prediction block for a current block by performing either inter-frame prediction or prediction using an intra-block copy mode; a step of deriving a transformation coefficient for a current block based on residual information for the current block; a step of deriving a de-quantized transformation coefficient by performing inverse quantization on the transformation coefficient; a step of deriving a residual block by performing at least one of non-separable inverse transformation or separate inverse transformation on the de-quantized transformation coefficient; and a step of restoring the current block from the residual block.

Inventors

이민훈
변주형
김민섭

Assignees

디지털인사이트 주식회사

Dates

Publication Date: 20260512
Application Date: 20251105
Priority Date: 20241105

Claims (11)

A step of generating a prediction block for the current block by performing either cross-frame prediction or prediction using an intra-block copy mode; A step of deriving a transformation coefficient for the current block based on residual information for the current block; A step of deriving inversely quantized transformation coefficients by performing inverse quantization on the above transformation coefficients; A step of inducing a residual block by performing at least one of a non-separable inverse transform or a separated inverse transform on the above-mentioned inverse quantized transform coefficients; and A video signal decoding method comprising the step of restoring the current block from the above residual block.
In paragraph 1, A video signal decoding method in which a first parameter indicating whether a non-separable inverse transform is performed for the current block is signaled.
In paragraph 2, Whether a non-separable inverse transformation is performed on the above current block is determined based on the first flag, but, The above first flag is a video signal decoding method that is signaled at the sequence level.
In paragraph 3, When the first flag is signaled at the sequence level, the second flag and the third flag are signaled at the sequence level, The second flag above is information indicating whether a non-separable inverse transformation is performed on a prediction block derived based on either an inter-frame prediction mode or an intra-block copy mode, and A video signal decoding method, wherein the third flag is information indicating whether a non-separable inverse transform is performed on a prediction block derived based on an in-frame prediction mode.
In paragraph 3, When the first flag is signaled at the sequence level, the second flag is signaled at the sequence level, A video signal decoding method, wherein the second flag is information indicating whether a non-separable inverse transformation is performed on a prediction block derived based on either an inter-frame prediction mode or an intra-block copy mode.
In paragraph 3, If at least one of the specified conditions is satisfied, the first parameter is signaled, A method for decoding an image signal, wherein the above predetermined conditions include at least one of a first condition in which the End Of Block (EOB) is greater than 3, a second condition in which the value of the first flag is true, a third condition in which the vertical kernel and the horizontal kernel applied to the separation inverse transformation are each DCTs, a fourth condition in which the width and height of the current block are each 16 or greater, or a fifth condition in which the EOB is less than or equal to 32.
In paragraph 2, A video signal decoding method in which a non-separable conversion kernel set is selected when the value of the first parameter above is not 0.
In Paragraph 7, The above inseparable transformation kernel set includes a plurality of inseparable transformation kernels, and A video signal decoding method in which one of the plurality of inseparable conversion kernels is selected based on inseparable conversion kernel set information.
In paragraph 8, A video signal decoding method in which, when either inter-frame prediction or prediction using an intra-block copy mode is performed for the current block, the non-separable conversion kernel set information is derived to 0.
A step of generating a prediction block for the current block by performing either cross-frame prediction or prediction using an intra-block copy mode; A step of deriving a residual block for the current block based on the above prediction block; A step of deriving a transformation coefficient for the current block by performing at least one of a non-separable transformation or a separable transformation based on the above residual block; A step of deriving quantized transformation coefficients by performing quantization on the above transformation coefficients; and A video signal encoding method comprising the step of encoding residual information regarding the above-mentioned quantized transform coefficients.
In a digital storage medium for storing a video bitstream, A digital storage medium encoded by an image signal encoding method comprising: a step of generating a prediction block for a current block by performing either inter-frame prediction or prediction using an intra-block copy mode on the bitstream; a step of deriving a residual block for the current block based on the prediction block; a step of deriving a transformation coefficient for the current block by performing at least one of non-separable transformation or separate transformation based on the residual block; a step of deriving a quantized transformation coefficient by performing quantization on the transformation coefficient; and a step of encoding residual information regarding the quantized transformation coefficient.

Description

Video coding method and apparatus, and recording medium storing bitstream The present invention relates to a video signal processing method and apparatus. More specifically, it relates to a method and apparatus for performing a quadratic transformation and an inverse transformation on a block for which prediction has been performed using an inter-frame prediction or intra-block copy mode. In the encoding process, first-order transformation (separation transformation) can be performed on the residual signal of a block that has been predicted by intra-frame prediction or inter-frame prediction to derive first-order transformation coefficients. Second-order transformation (non-separation transformation) can be performed on all or part of the first-order transformation coefficients to derive second-order transformation coefficients. In the decoding process, inverse quantized transform coefficients are obtained from blocks where prediction is performed via intra-frame prediction or inter-frame prediction, and a second-order inverse transform and a first-order inverse transform are performed on them to recover the final residual signal. FIG. 1 is a block diagram showing an image encoding device according to the present disclosure. FIG. 2 is a block diagram showing an image decoding device according to the present disclosure. FIG. 3 is a flowchart of an image signal encoding method according to one embodiment of the present disclosure. FIG. 4 is a drawing illustrating a directional prediction mode according to the present disclosure. FIG. 5 is a drawing illustrating a directional prediction mode according to the present disclosure. FIG. 6 is a diagram illustrating an example of deriving a directional prediction mode corresponding to a geometric division mode according to the present disclosure. FIG. 7 is a drawing illustrating an example of inducing directionality within a prediction block according to the present disclosure. FIG. 8 is a diagram illustrating an example of determining an in-frame prediction mode through a reference line in geometric division-based prediction according to the present disclosure. FIG. 9 is a flowchart of an image signal decoding method according to one embodiment of the present disclosure. Embodiments of the present invention are described in detail with reference to the drawings attached to this specification so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification are denoted by similar reference numerals. Throughout this specification, when a part is described as being 'connected' to another part, this includes not only cases where they are directly connected, but also cases where they are electrically connected with other elements in between. Furthermore, throughout this specification, when a part is described as 'comprising' a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Additionally, terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. Additionally, in the embodiments relating to the device and method described herein, some components of the device or some steps of the method may be omitted. Also, the order of some components of the device or some steps of the method may be changed. Additionally, other components or other steps may be inserted into some components of the device or some steps of the method. In addition, some components or steps of the first embodiment of the present invention may be added to or replace some components or steps of the second embodiment of the present invention. Furthermore, the components shown in the embodiments of the present invention are depicted independently to represent different characteristic functions and do not imply that each component consists of separate hardware or a single software unit. That is, for convenience of explanation, each component is described by listing it as a separate component, and at least two of the components may be combined to form a single component, or a single component may be divided into multiple components to perform a function. Such integrated and separated embodiments of each component are also included within the scope of the present invention as long as they do not deviate from the essence of the invention. FIG. 1 is a block diagram showing an image encoding device according to the present disclosure. Referring to FIG. 1, the image encoding device (100) comprises a picture splitting unit (110), a prediction