In one embodiment, loop-filtering is performed by a decoder on four successive pixels if obtained quantization information for a first block is greater than the threshold value and the type of the first block and a second block is intra-coded block type. Two pixels of the four successive pixels are in the first block and two pixels of the four successive pixels are in the second block, which is adjacent the first block. The decoder is also configured to perform additional filtering on two successive pixels on the block boundary based on a comparison result of the quantization information and a second threshold value.