一個改良LBG初始編碼簿與收斂方法之影像壓縮技術

An Image Compression Technique Based on Initial Codebook Improvement and Convergence Improvement of LBG

吳冠賦(Kuan-Fu Wu)

指導教授 ： 蔡正發

國立屏東科技大學/管理學院/資訊管理系所/碩士(2016年)

摘要

本論文將進行「影像壓縮」之研究，影像壓縮簡略的定義即是減少一張影像所需要的訊號空間數量，進而使傳遞變得迅速，而能夠達到影像壓縮的方法眾多，概括可分類為「頻率領域」及「空間領域」，而這兩個領域又可再分為「失真性」與「無失真性」壓縮，本研究基於「空間領域」中「失真性」影像壓縮的LBG演算法，進行改良，並命名為AICT。
　　AICT有五個重要部分：(1)擷取影像有用之數據(2)利用影像特徵產生較好的初始編碼簿(3)根據影像類型自動產生參數(4)減少重複顏色進而使執行時間減少(5)改善收斂方法進而加速演算法運行。
　　AICT有以下優點：(1)無須自行輸入參數即可執行(2)程式操作容易(3)壓縮品質優異且執行時間良好(4)演算法效能實驗中，展現良好競爭力。

關鍵字

影像壓縮 ； 分群技術 ； 自動化方法

並列摘要

This thesis performs the research in image compression. Image compression means to reduce the storage for saving images and even make sending data more quickly. There are many ways to conduct image compression. It can be classified into two categories which are frequency domain and spatial domain. Moreover, they are subdivided into lossy compression and lossless compression. This thesis mainly discusses the LBG algorithm in lossy image compression of spatial domain and improve it with good performance. The new technique was named AICT.
　　There are five important parts in AICT: (1) Deal with image to obtain useful information before executing algorithm. (2) Use image’s feature to produce the better initial codebook. (3) Get the parameters by automation methods from image’s types. (4) Reduce repeating color to decrease the time. (5) Ameliorate the convergence method to accelerate algorithm.
　　This thesis includes following advantages: (1) AICT can implement without keying in parameters. (2) Work is simple and easy to understand (3) The quality in compression is excellent and has good execution time. (4) Finally, the experiments show the comparison among LBG, SOM, and LazySOM. AICT expresses the nice competitiveness in each test.

並列關鍵字

image compression ； clustering technique ； automated method

參考文獻

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