Fast LOT with unequal length basis functions: Realization and application in subband image coding

作     者：Nagai, T Ikehara, M 

作者机构：Univ Electrocommun Dept Elect Engn Chofu Tokyo 1828585 Japan Keio Univ Dept Elect Engn Yokohama Kanagawa 2238522 Japan 

出 版 物：《IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES》 (IEICE Trans Fund Electron Commun Comput Sci)

年 卷 期：1999年第E82A卷第5期

页      面：825-834页

核心收录：

学科分类：0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

主　　题：lapped transform fast algorithm subband image coding 

摘      要：In this paper, the Lapped Orthogonal Transform (LOT) with unequal length basis function is considered. The proposed unequal length LOT (ULLOT) has both long basis of length 2M and short basis of length M, while the lengths of all bases of the conventional LOT are 2M. A new class of LOT can be constructed with some modifications of Malvar s Fast LOT. Therefore, the fast algorithm for the Discrete Cosine Transform (DCT) will surely facilitate the computation of the ULLOT. Although the computational complexity of the ULLOT is always lower than that of the LOT, there exist some cases where the coding gain of the ULLOT becomes slightly higher than that of the LOT. Its ability to reduce ringing artifacts is an attractive feature as well. The size-limited structure for the finite length signal is investigated and the ULLOTs are tested on image coding application. The simulation results confirm the validity of the proposed ULLOT.