Method and apparatus for encoding/decoding images considering low frequency components

A method performed by an apparatus for decoding a current block, the method comprising:

• reconstructing, from a bitstream, a flag indicating whether offset information is encoded, wherein the offset information indicates offset values for compensating for distortion between original pixels and reconstructed pixels;
• reconstructing the offset information from the bitstream, when the flag indicates that the offset information is encoded;
• generating a predicted block of the current block to be decoded by predicting the current block;
• partitioning the current block into a plurality of subblocks, wherein the current block is allowed to be partitioned into the subblocks having various sizes;
• generating transform blocks corresponding to the subblocks, by extracting, from the bitstream, transform coefficients corresponding to each of the subblocks;
• inversely quantizing and then inversely transforming each of the transform blocks by using a transform unit of a size identical to a corresponding subblock, and thereby reconstructing residual subblocks corresponding to the subblocks;
• generating a residual block of the current block by, the residual block comprised of the reconstructed residual subblocks;
• reconstructing the current block by adding the predicted block and the generated residual block;
• deblocking-filtering the reconstructed current block;
• and
• adding reconstructed pixels in the deblocking-filtered current block and the offset values derived from the reconstructed offset information, when the flag indicates that the offset information in encoded.