サブバンドおよびベクトル量子化と組み合わせたフラクタル画像符号化

Abstract

In order to improve the performance of fractal image coding, this paper proposes two new coding schemes which are combined with sub-band decomposition and vector quantization. In the first proposed scheme, fractal block coding or vector qantization is employed block by block adaptively. In the second proposed scheme, an input image is first decomposed to low and high resolution sub-band images. The fractal block conding with adaptive range block size is performed only for the lowest resolution sub-band image. On the other hand, vector quantization is carried out for the other high resolution sub-band images. The results by computer simulation experiments show that the two proposed coding schemes give higher SNR (Signal-to-Noise Ratio) values and better reconstructed image qualities compared to the conventional fractal block coding scheme.