An efficient error concealment algorithm for DCT encoded images

In order to improve the quality of DCT encoded images when transmitted over noisy communication channel or packet networks, an efficient error concealment algorithm is proposed. The algorithm makes full use of the available information, considering the consistency, smoothness, and statistical correlation properly in image, instead of one of them. The algorithm is computationally simple, making it very beneficial for real time processing. The algorithm is based on the underlying hypothesis that the loss concerns an isolated block, while all the surrounding blocks are correctly received. In the algorithm, the different lost blocks have the different weighting coefficients. The weighting coefficients are adoptively adjusted to work robustly in smooth or abruptly-changing region. In addition, we analyze the computational complexity of several published algorithms. In order to prove the efficacy of the proposed algorithm we make an extensive testing phase, performed on a large set of images with different features. Testing results reveal that the proposed algorithm provides very reconstruction capabilities, and the concealed image quality is improved notably.