A block classification algorithm for DCT-based digital video coding

This paper presents a new block classification algorithm for block filtering in the DCT-based digital video coding. In general, linear block filters are applied to every block on the reconstructed image regardless of their degree of visibility to reduce the blocking artifacts. The method proposed in this paper allows the coding scheme to identify the blocks that are apparent and significantly contribute to the overall blocking artifacts so that the block filters can be applied only to those blocks. The method calculates the block classification parameter from the original image and transmitted or stored to be used as a threshold value in the block classification process at the decoding stage.