A fast index-linked method based on embedded zerotree wavelet image coding
碩士 === 國立海洋大學 === 電機工程學系 === 90 === Image compression plays a very important role on data transmission and storage. Compared with JPEG, the wavelet-based impression does not produce the blocking artifact. In recent years, there has been a growing interest in wavelet-based image compressi...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2002
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| Online Access: | http://ndltd.ncl.edu.tw/handle/48532284402195052948 |
| Summary: | 碩士 === 國立海洋大學 === 電機工程學系 === 90 === Image compression plays a very important role on data transmission and storage. Compared with JPEG, the wavelet-based impression does not produce the blocking artifact. In recent years, there has been a growing interest in wavelet-based image compression algorithm. Shapiro’s Embedded Zerotree Wavelet coder (EZW) is a very simple and effective techinque for image impression. However, it is found that there is still room for improvement in EZW. In this paper, we proposed an improvement of EZW coding to speed up the encoder. It is a fast index-link method based on embedded zerotree wavelet image coding. The modified algorithm increases four symbols to eight symbols and preserves the position which previous found significant coefficients. The output of encoder is couple of symbols. It improves the efficiency of encoder in the dominant pass. The advantages of this algorithm are to reduce the encoding of the ZTR symbol and the ZTR symbol can be found early in the first several passes. Computer simulations show that this proposed algorithm has better performance than conventional EZW in intermediate or low bit rate. This encoding algorithm also retains most properties of EZW.
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