A new method of reducing boundary artifacts for JPEG2000 multi-tile coding

In this paper, we present the pre-/post-filtering framework to reduce the boundary artifacts introduced by JPEG2000 multi-tile coding. Compared to taking one-dimension array as the input model as common did, two-dimension (2D) matrix is adopted to make the derivations more precisely. To build the statistical relationship between the input image and the distortion of the reconstructed image, we present the analysis of the 2D discrete wavelet transform (DWT) with the pre-filter, the 2D inverse DWT with the post-filter, and the distortion model of the scalar dead-zone quantization. Furthermore, the measure standard is formulated in terms of the memory cost and the relative size of the mean square error on boundary and non-boundary coefficients. Based on several experiments, the optimal pre-/post-filters of typical sizes are obtained, and their great performance in reduction of boundary artifacts is proved.