Method for encoding and decoding image information
The present invention relates to a method for encoding and decoding image information and to an apparatus using same, and the method for encoding the image information, according to the present invention, comprises the steps of: generating a recovery block; applying a deblocking filter to the recovery block; applying a sample adaptive offset (SAO) to the recovery block to which the deblocking filter is applied; and transmitting the image information including information on the SAO which is applied, wherein in the step of transmitting, information for specifying bands that cover a scope of a pixel value, to which a band off set is applied, is transmitted when the band offset is applied during the step of applying the SAO.
1. An method of video decoding using a filter for a sample, the method comprising:
receiving video information including residual information for deriving a residual sample, prediction information for indicating prediction mode, and offset information for applying offset to a sample;
deriving a prediction sample based on prediction mode indicated by the prediction information;
deriving a residual sample based on the residual information;
generating a reconstructed picture using the prediction sample and the residual sample;
applying a sample adaptive offset (SAO) process to the sample in the reconstructed picture based on the offset information,
wherein the offset information includes offset type information for indicating offset type to be applied, and
wherein the offset information includes band information indicating one of 32 bands as a starting band of a band group consisting of n (n is integer) bands, the band group is determined based on the starting band, and the offset is applied to the sample based on a band among n bands.
2. The method of claim 1 , wherein the band is determined as a predetermined sample value range to which the sample belongs.
3. The method of claim 2 , wherein the n bands are specified as the starting band and following bands according to sample value order, wherein the offset is determined based on the band to which the sample belongs.
4. The method of claim 1 , wherein the band information indicates a last band among the n bands.
5. The method of claim 4 , wherein the n bands are bands for which information indicating offset values is transmitted.
6. The method of claim 4 , wherein the available bands are specified as the last band and bands followed by the last band according to sample value order, wherein the offset is determined based on a band which the sample corresponds to.
7. The method of claim 1 , wherein in the step of obtaining video information, the offset type information is obtained by context-adaptive arithmetic coding.
8. The method of claim 1 , wherein the offset information is transmitted for a unit which is split from a picture.
9. The method of claim 1 , wherein the offset is applied to the sample based on the offset information which is transmitted for largest coding unit to which the sample belongs.