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Please use this identifier to cite or link to this item: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/35696

Title: 四分樹分割影像壓縮
Quadtree Segmented Image Compression
Authors: Ssu-Han Cheng
Contributors: NTOU:Department of Communications Navigation and Control Engineering
Keywords: 四分樹影像切割;小波轉換;餘弦轉換;差分脈碼調變
Quadtree Image Segmentation;Discrete Wavelet Transform;Discrete Cosine Transform;Differential Pulse Coded Modulation
Date: 2012
Issue Date: 2013-10-07T02:57:58Z
Abstract: 本論文主要探討四分樹影像切割技術對於影像壓縮的效益。四分樹影像切割技術使切割後的影像區塊能趨近穩定特性進而達到較佳的壓縮效能。依給定條件下,四分樹影像切割技術將原始影像切割成不同大小的影像區塊,原始影像區塊經過切割分別在空間域與頻域進行壓縮。 影像在空間域轉頻域部分,選擇兩種方法分別為離散餘弦轉換(Discrete Cosine Transform, DCT)與離散小波轉換(Discrete Wavelet Transform, DWT),再搭配位元分配觀念利用向量量化進行壓縮。空間域壓縮部分,本文使用差分脈波編碼調變(Differential Pulse Coded Modulation, DPCM)將四分樹切割後的影像區塊進行壓縮。最後比較三種方法的模擬實驗結果,分析四分樹影像切割法對於不同壓縮方法的效果。
In this study, we focus on the effectiveness of the Quadtree Image Segmentation techniques for image compression. We use the Quadtree Image Segmentation technology to improve image stability. Dividing the image block’s pixels can increase stability and thus achieve better compression performance. Using Quadtree Image Segmentation technology, we can compress the divided image block in spatial domain and frequency domain. We select two algorithms – DCT and DWT – to transfer images from spatial domain to frequency domain, and use the bit allocation and vector quantization methods to compress the image. For compression in spatial domain, we use Differential Pulse Coded Modulation (DPCM) to compress image block after the Quadtree Image Segmentation. Finally, we use the three methods mentioned above to run simulations and compare their Peak Signal to Noise Ratio (PSNR). With the data collected, we analyze the efficiency of the Quadtree Image Segmentation techniques for image compression.
URI: http://ethesys.lib.ntou.edu.tw/cdrfb3/record/#G0019967017
Appears in Collections:[通訊與導航工程學系] 博碩士論文

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