Content Analysis-based Adaptive Filtering in The Compressed Satellite Images
Taehyeon Choi, Jeong-Min Ji, Joon-Hoon Park, Myungjin Choi, Sangkeun Lee · Journal of the Institute of Electronics Engineers of Korea · 2011
In this paper, we present a deblocking algorithm that removes grid and staircase noises, which are called artifacts, occurred in the compressed satellite images. Particularly, the given satellite images are compressed with equal quantization coefficients in row according to region complexity, and more complicated regions are compressed more. However, this approach has a problem that relatively less complicated regions within the same row of complicated regions have blocking artifacts. Removing these artifacts with a general deblocking algorithm can blur complex and undesired regions as well. Additionally, the general filter lacks in preserving the curved edges. Therefore, the proposed algorithm presents an adaptive filtering scheme for removing blocking artifacts while preserving the image details including curved edges using the given quantization step size and content analysis. Particularly, WLFPCA (weighted lowpass filter using principle component analysis) is employed to reduce the artifacts around edges. Experimental results showed that the proposed method outperforms SA-DCT in terms of subjective image quality.