Method for encoding/decoding image and device thereof
A method for image decoding, according to the present invention, includes the following steps: receiving image information including a plurality of filter coefficients; generating a restored block for a current block on the basis of the image information; and applying an adaptive loop filter to the restored block on the basis of the plurality of filter coefficients. According to the present invention, image encoding efficiency may be improved, and complexity may be reduced.
1. An image encoding method by an encoding apparatus, comprising:
deriving prediction samples for a current picture;
generating a reconstructed picture based on the prediction samples;
applying an in-loop filtering process to the reconstructed picture;
generating prediction information for a prediction process;
generating offset information for a sample adaptive offset (SAO) process; and
encoding image information including the prediction information and the offset information,
wherein applying the in-loop filtering process includes applying a deblocking filtering process to the reconstructed picture, and applying the SAO process to a sample in the reconstructed picture on which the deblocking filtering process is completed,
wherein the offset information includes offset type information indicating a SAO type applied to the sample, and
wherein based on the offset type information indicating that a band offset type is applied to the sample, the offset information includes explicit band information indicating one of 32 bands as a starting band of a band group consisting of n bands, and an offset corresponding to a band among the n bands is applied to the sample, wherein n is an integer.
2. A transmission method of data for an image, the transmission method comprising:
obtaining a bitstream generated by a method, the method comprising deriving prediction samples for a current picture, generating a reconstructed picture based on the prediction samples, applying an in-loop filtering process to the reconstructed picture, generating prediction information for a prediction process, generating offset information for a sample adaptive offset (SAO) process, and encoding image information including the prediction information and the offset information; and
transmitting the data comprising the bitstream,
wherein applying the in-loop filtering process includes applying a deblocking filtering process to the reconstructed picture, and applying the SAO process to a sample in the reconstructed picture on which the deblocking filtering process is completed,
wherein the offset information includes offset type information indicating a SAO type applied to the sample, and
wherein based on the offset type information indicating that a band offset type is applied to the sample, the offset information includes explicit band information indicating one of 32 bands as a starting band of a band group consisting of n bands, and an offset corresponding to a band among the n bands is applied to the sample, wherein n is an integer.