Patent ID: 7844124

Claim:
A method of estimating a quantization parameter (QP), applied to a de-blocking filter, the de-blocking filter de-blocking a decoded block-based image according to the quantization parameter, the block-based image being coded and decoded in units of macroblocks, the method comprising: (a) calculating blocking degrees of a plurality of block edges corresponding to the macroblocks; calculating a sum of luminance absolute differences of a plurality of pairs of inter pixels next to the block edge in two adjacent macroblocks of the block edge and a sum of luminance absolute differences of a plurality of pairs of intra pixels next to the block edge in one of the two adjacent macroblocks; and determining the blocking degree of each block edge according to a ratio of the sum of luminance absolute differences of the pairs of inter pixels next to the block edge in the two adjacent macroblocks of the block edge and the sum of luminance absolute difference of the pairs of intra pixels next to the block edge in one of the two adjacent macroblocks; and (b) estimating the quantization parameter according to a sum of the blocking degrees.