Fast Partial Codebook Search Algorithm for Vector Quantization

• Main Authors: Chien-Liang Kuo, 郭建良
• Other Authors: Hung-Min Sun
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/91097170823278569147

碩士 === 國立成功大學 === 資訊工程學系碩博士班 === 91 === In this thesis, we propose two methods which base on mean-sorted method , to filter the impossible codeword in advance, expecting to reduce the times of the calculation of Euclidean Distance in the Encoding times.In these algorithms,we choice different projection masks for each codeword by it''s pixels value, and store in the Codebook;Or after producing the codebook , producing a unique projection mask for each codeword according to it''s distribution of pixels value.When compressing,take out the previous records, and set these on the codeword and source vectors, then use the distortion measure function to judge.If the result which was calculated by that method is matched,then calculate the Euclidean Distance further. Our proposed method is base on MPS, and can avoid unnecessary calculaion of the Euclidean Distance. Because when we search in the codebook, we do not need to calculate the SED value and can judge whether this codeword is the closest codeword;Besides, it is proved this method can reduce the calculation quantity effectively through experiment.In addition, because this method is not only fix in a certain projection mask.And can choice different types according to difference of vector，so it has much flexibility. its effect also has the good performance equally in all types of pictures.