18-10-2010, 02:12 PM
Tran Duc Hai Du
Abstract
A complexity reduction algorithm for an H.264 encoder is proposed. This comes at the cost of the number of increased macroblock modes and the complex mode decision procedure using the rate-distortion optimization [1]. H.264 demands a high degree of computational complexity to be able to make use of the advantages of its new techniques. Experiment results in [1] show that the proposed algorithm can reduce the encoding time by 29.67% on average and the rate-distortion computation by 89.14% (depending on the source sequence) with no significant loss of rate-distortion performance. In this paper, before transmitting images through any channels, we must compressed image using H.264. However, missing image blocks still occur due to the problem of transmission. An approach for filling-in blocks of missing data in H.264 image transmission is presented. In this paper, H.264 compression is used for lossy JPEG as part of the transmission process, images are first titled into blocks of 8x8 pixels. When such images are transmitted over fading channels, the effects of noise can kill entire blocks of the image. Instead of using common retransmission query protocols, we aim to reconstruct the lost data using correlation between the lost block and its neighbors. If the lost block contained structure, it is reconstructed using an image in-painting algorithm, while texture synthesis is used for the textured blocks. The switch between the two schemes is done in a fully automatic fashion based on the surrounding available blocks. The performance of this method is tested for various images and combinations of lost blocks. The viability of this method for image compression, in association with lossy JPEG is also discussed.
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