US-20260129183-A1 - ENCODING/DECODING METHOD AND APPARATUS FOR INTRA PREDICTING A CODING UNIT PARTITION

US20260129183A1US 20260129183 A1US20260129183 A1US 20260129183A1US-20260129183-A1

Abstract

Disclosed is an image decoding method using the correlation between color components to perform into prediction of chrominance components. Here, the image decoding method using the correlation between color components to perform intra prediction of chrominance components comprises the steps of: checking image data and a prediction mode in a bitstream; generating a prediction block according to a reconstructed prediction mode; determining compensation settings according to the size of a current block and the reconstructed prediction mode; compensating the prediction block according to the determined compensation settings; and reconstructing the current block by adding reconstructed image data to the prediction block.

Inventors

Ki Baek Kim

Assignees

B1 INSTITUTE OF IMAGE TECHNOLOGY, INC.

Dates

Publication Date: 20260507
Application Date: 20251230
Priority Date: 20180115

Claims (3)

1 . An image decoding method performed by an image decoding apparatus, the image decoding method comprising: obtaining a current block by dividing the image; determining reference samples for a current sample included in the current block, the reference samples being obtained from one or more neighboring blocks of the current block; predicting the current sample based on the reference samples to generate a prediction sample for the current sample; and correcting the prediction sample, wherein at least one reference sample among the reference samples is determined based on position of the current sample, wherein the current sample is predicted using interpolation of the reference samples, wherein the one or more neighboring blocks is selected from a plurality of candidates including a left neighboring block, a top neighboring block and both of the left neighboring block and the top neighboring block based on a non-directional prediction mode of the current block, wherein the reference samples obtained from both of the left neighboring block and the top neighboring block include a first reference sample located at (w−1, −1) and a second reference sample located at (−1, h−1) in case a top-left sample position of the current block is (0, 0), a width of the current block is w and a height of the current block is h, and wherein the prediction sample for the current sample is corrected using a setting determined based on the non-directional prediction mode.
2 . An image encoding method performed by an image encoding apparatus, the image encoding method comprising: obtaining a current block by dividing the image; determining reference samples for a current sample included in the current block, the reference samples being obtained from one or more neighboring blocks of the current block; predicting the current sample based on the reference samples to generate a prediction sample for the current sample; and correcting the prediction sample, wherein at least one reference sample among the reference samples is determined based on position of the current sample, wherein the current sample is predicted using interpolation of the reference samples, wherein the one or more neighboring blocks is selected from a plurality of candidates including a left neighboring block, a top neighboring block and both of the left neighboring block and the top neighboring block based on a non-directional prediction mode of the current block, wherein the reference samples selected from both of the left neighboring block and the top neighboring block include a first reference sample located at (w−1, −1) and a second reference sample located at (−1, h−1) in case a top-left sample position of the current block is (0, 0), a width of the current block is w and a height of the current block is h, and wherein the prediction sample for the current sample is corrected using a setting determined based on the non-directional prediction mode.
3 . A method of generating a bitstream and transmitting the bitstream, the method comprising: obtaining a current block by dividing the image; determining reference samples for a current sample included in the current block, the reference samples being obtained from one or more neighboring blocks of the current block; predicting the current sample based on the reference samples to generate a prediction sample for the current sample; correcting the prediction sample; generating the bitstream based on the corrected prediction sample; and transmitting the bitstream, wherein at least one reference sample among the reference samples is determined based on position of the current sample, wherein the current sample is predicted using interpolation of the reference samples, wherein the one or more neighboring blocks is selected from a plurality of candidates including a left neighboring block, a top neighboring block and both of the left neighboring block and the top neighboring block based on a non-directional prediction mode of the current block, wherein the reference samples selected from both of the left neighboring block and the top neighboring block include a first reference sample located at (w−1, −1) and a second reference sample located at (−1, h−1) in case a top-left sample position of the current block is (0, 0), a width of the current block is w and a height of the current block is h, and wherein the prediction sample for the current sample is corrected using a setting determined based on the non-directional prediction mode.

Description

RELATED APPLICATIONS This application is a continuation application of U.S. patent application Ser. No. 19/314,342, filed Aug. 29, 2025, which is a continuation application of U.S. patent application Ser. No. 18/410,710, filed Jan. 11, 2024, which is now U.S. Pat. No. 12,425,575, which is a continuation application of U.S. patent application Ser. No. 18/478,555, filed Sep. 29, 2023, which is now U.S. Pat. No. 12,113,967, which is a continuation application of U.S. patent application Ser. No. 17/750,726, filed May 23, 2022, which is now U.S. Pat. No. 11,838,499, which is a divisional application of U.S. patent application Ser. No. 17/109,135, filed Dec. 1, 2020, which is now U.S. Pat. No. 11,381,809, which is a divisional application of U.S. patent application Ser. No. 16/880,788, filed May 21, 2020, which is now U.S. Pat. No. 11,012,689, which is a continuation application of the international application No. PCT/KR2019/000436, filed Jan. 11, 2019, which claims priority to the Korean patent application No. 10-2018-0005294, filed Jan. 15, 2018. All of these applications are incorporated by reference herein in their entireties. TECHNICAL FIELD The present invention relates to an image encoding/decoding method and apparatus for chrominance components. More specifically, it relates to a method and apparatus for generating prediction blocks based on correlation information between color components, and reducing deterioration between blocks by applying correction to the generated prediction blocks. BACKGROUND With the spread of the Internet and portable terminals and the development of information communication technology, the use of multimedia data is rapidly increasing. Accordingly, the need for improving the performance and efficiency of an image processing system has been significantly increased to perform various services or tasks through image prediction in various systems, but research and development results that can respond to this atmosphere are insufficient. As described above, in the conventional image encoding and decoding method and apparatus, performance improvement in image processing, particularly image encoding or image decoding, is required. SUMMARY An object of the present invention for solving the above problems is to provide an image encoding/decoding method and apparatus for performing intra prediction by utilizing a correlation between color components. A method of decoding an image according to an embodiment of the present invention for achieving the above object may comprise checking image data and a prediction mode in a bitstream, generating a prediction block according to a restored prediction mode, determining a correction setting according to a size of a current block and the restored prediction mode, compensating the prediction block according to the determined correction settings, and restoring the current block by adding the reconstructed image data and the prediction block. Herein, the step of determining the correction setting may further comprise determining whether to perform the correction according to the size of the current block and a type of the prediction mode. Herein, the step of determining the correction setting may further comprise determining a region to be corrected according to the size of the current block and the type of prediction mode. When using a method for performing intra prediction by utilizing a correlation between color components according to the present invention as described above, prediction accuracy is high and encoding performance can be improved. In addition, since correction is performed on a boundary region of a prediction block, there is an advantage that block degradation can be reduced. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a conceptual diagram of an image encoding and decoding system according to an embodiment of the present invention. FIG. 2 is a block diagram of an image encoding apparatus according to an embodiment of the present invention. FIG. 3 is a block diagram of an image decoding apparatus according to an embodiment of the present invention. FIG. 4 is an exemplary diagram illustrating an intra prediction mode according to an embodiment of the present invention. FIG. 5 is a conceptual diagram illustrating intra prediction for a directional mode and a non-directional mode according to an embodiment of the present invention. FIG. 6 is a conceptual diagram illustrating intra prediction regarding a color copy mode according to an embodiment of the present invention. FIG. 7 is an exemplary diagram illustrating a corresponding block of each color space and a region adjacent thereto in relation to a color copy mode according to an embodiment of the present invention. FIG. 8 is an exemplary diagram for explaining a reference pixel configuration used for intra prediction according to an embodiment of the present invention. FIG. 9 is a conceptual diagram illustrating a block adjacent to a target block for intra prediction according to an e