Modified cubic convolution scaler for multiformat conversion in a transcoder

作     者：Han, JK Kim, HM 

作者机构：Sejong Univ Dept Informat & Commun Engn Seoul South Korea Korea Adv Inst Sci & Technol Dept Elect Engn Taejon 305701 South Korea 

出 版 物：《OPTICAL ENGINEERING》 (光学工程)

年 卷 期：2004年第43卷第7期

页      面：1596-1608页

核心收录：

学科分类：08[工学] 080401[工学-精密仪器及机械] 0804[工学-仪器科学与技术] 081102[工学-检测技术与自动化装置] 0811[工学-控制科学与工程] 0702[理学-物理学] 

基　　金：National Research Foundation of Korea  NRF  (KRF-2002-003-D00224) 

主　　题：scaler cubic convolution interpolation transcoder 

摘      要：We derive a modified version of cubic convolution interpolation for the enlargement or reduction of digital images by arbitrary scaling factors. The proposed scaling scheme is used to resize various format pictures in the transcoding system, which transforms the bitstream compressed at a bit rate, such as the HD bitstream, into another bit rate stream, for example, the SD bitstream. The transcoding is performed in spatial domain. In many applications such as the transcoder, the resolution conversion is very important for changing the image size while the scaled image maintains high quality. The scaling process consists of two steps: fitting the original data with a continuous function, and resampling the function on a new sampling grid. We focus on the modification of the scaler kernel according to the relation between formats of the original and the resized image. In the modification, various formats defined in MPEG standards are considered. We show experimental results that demonstrate the effectiveness of the proposed interpolation method. The algorithm exhibits significant improvement in the minimization of information loss when compared with the conventional interpolation algorithms. (C) 2004 Society of Photo-Optical Instrumentation Engineers.