An Index Assignment Algorithm for Improving the Transmission of Vector-Quantized Images over a Rayleigh Fading Channel
Waslon Terllizzie Araújo Lopes, F. Madeiro, Marcelo S. Alencar
Evento: XVIII Simpósio Brasileiro de Telecomunicações (SBrT2000)
Abstract"A serious problem related to the transmission of vector-quantized images through noisy channels is that whenever errors occur, the nearest neighbor rule is broken. As a consequence, very annoying blocking effects may appear in the reconstructed images. In the present work, a simple and fast method for organizing the vector quantization (VQ) codebooks is presented. The key idea behind the proposed method is to ensure that similar (dissimilar) binary representations of the indexes of the codevectors correspond to similar (dissimilar) codevectors themselves. It is shown that the organized codebooks improve the performance of the transmission system in the sense that they lead to reconstructed images with better quality when compared to the ones obtained by using non-organized codebooks."