Method of removing a blocking artifact using quantization information in a filtering system

A method of removing a blocking artifact using quantization information in a filtering system, comprising:

• obtaining quantization information related to at least one of a first block and a second block, the second block being adjacent to the first block;
• comparing the quantization information with a predefined constant value that remains fixed over more than one execution of a filtering process for a plurality of frames to determine whether the quantization information is greater than or less than or equal to the predefined constant value;
• obtaining block type information for the first and second block, the block type information indicating whether a block is an intra-coded block;
• and
• performing the filtering process based on a result from the comparing step when at least one of the first block and the second block is the intra-coded block according to the block type information,
• the filtering process including,
• obtaining a filtered value of at least one pixel in the first block based on values of at least two pixels in the first block,
• wherein the at least two pixels in the first block are successive pixels in the first block.