画像の処理と符号化 動画像符号化におけるサブバンド分割を用いた高速Ｍａｔｃｈｉｎｇ Ｐｕｒｓｕｉｔｓアルゴリズム

Abstract

A high-efficiency video coding method using matching pursuits, which is a waveform coding technique, was proposed. This method encodes a motion compensated prediction error image by applying matching pursuits. The matching pursuits algorithm approximates a signal using a dictionary. Therefore, the performance of this algorithm depends heavily on the dictionary. We propose a matching pursuits coding method that encodes the sub-band images derived from motion compensated prediction error images. The dictionaries used in our method are constructed to be suitable for the frequency characterisitc of each sub-band image. The complexity of our method is reduced compared with the full-band matching pursuits because of lighter inner product computation due to a reduction in both the resolution of the sub-band image and the basis function length of the dictionary. We evaluated the coding performance and computational complexity of our method via computer simulations.