1. An apparatus for removing a blocking phenomenon using properties of two blocks, comprising: a decoder configured to determine whether at least one of a first block and a second block has non-zero transform coefficient information, and the second block being adjacent to the first block, the decoder further configured to, determine a filter strength value in consideration of a presence of the non-zero transform coefficient information, determine coefficients, for pixels on a block boundary between the first and second blocks, based on the filter strength value, calculate values of the pixels based on the determined coefficients, and a bit shift operation, wherein the bit shift operation uses an integer, wherein the integer is greater than one, and wherein the pixels on the block boundary are at least two pixels in the first block and at least two pixels in the second block.