小波頻域上免搜尋碎形影像編碼

NO SEARCH FRACTAL IMAGE CODING IN WAVELET DOMAIN

林君屏(Jun-Ping Lin)

指導教授 ： 汪順祥

大同大學/電機資訊學院/通訊工程研究所/碩士(2008年)

摘要

免搜尋碎形影像編碼(no search fractal image coding)比起傳統碎形影像編碼(full search fractal image coding)的編碼數度快很多。在這篇論文中我們提出將免搜尋碎形影像編碼方法用在小波頻域上，這個方法可以使編碼速度更快且擁有高的壓縮率。此方法是將在小波轉換中不同階頻域中的值域方塊(range block)用固定位置的定義域方塊(domain block)來做編碼，我們利用小波轉換不同階頻域之間的關係去減少編碼的時間。實驗結果顯示我們提出來的方法的編碼速 度比免搜尋碎形影像編碼和在小波頻域上的無搜尋碎形影像編碼(searchless fractal image coding)來的快，而且壓縮率也比小波頻域上的無搜尋碎形影像編碼方式來的高。

關鍵字

小波轉換 ； 碎形壓縮編碼 ； 免搜尋

並列摘要

The no search fractal image coding method is very fast compared with the full search fractal image coding method. In this thesis, we propose no search fractal coding in wavelet domain method that can make encoding speed faster and have high compression ratio. This method uses fractal code on wavelet domain. Encoded image range blocks utilize fixed location domain blocks in different wavelet scale. We utilize the correlation of different wavelet scale to reduce encoding time. Experiment result show that the encoding time of proposed method is faster than the no search method and searchless in wavelet domain. It is show that the compression ratio and the reconstructed quality of our method are better than the method of searchless fractal coding in wavelet domain.

並列關鍵字

wavelet transform ； fractal image coding ； no search

參考文獻

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[5] Junli Li, Gang Chen and Zheru Chi, “A fuzzy image metric with application to fractal coding,” IEEE Transactions on Image Processing, Vol. 11, No 6, pp.636 – 643, June 2002.