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  • 學位論文

利用浮水印技術於影像破壞區域之偵測與修補

The polluted image detection and inpainting using watermarking technique

指導教授 : 謝景棠

摘要


常見的影像修復技術,主要的瓶頸在於邊緣的修復。為了解決修補 法在確定影像邊緣上的難題,還有修補時,提升正確性,本文提出一利 用浮水印技術用於影像破壞區域之偵測與修補。 我們將原圖之重要邊緣抽出,視為強健型浮水印,再嵌入於原圖做 一階小波之後的1 LL 位置中,以作為修補比對之參考。本技術亦嵌入一易 碎型浮水印,修復系統可藉由抽取易碎型浮水印,自動偵測待測影像之 破壞區域,同時利用抽取出之強健型浮水印(重要邊緣),依照其重要邊 緣紋理,進行階層式修補,包含區塊修補法及結構擴展法。但是同時嵌 入兩個浮水印,又要提升嵌入之後的影像PSNR 值,是很困難的。所以 我們利用小波轉換與VQ 結合,來減少需要嵌入的資料量。由實驗結果 可證實,嵌入浮水印之後,測試影像仍然不易察覺的優點,受破壞之後, 本技術可自動偵測破壞區域,並成功修補之。

並列摘要


In image completion and inpainting technique,the key issue is edge restoration. In order to resolve the image inpainting problem in the object edge and to enhance the accuracy of the original image during repairing, we presents a multi-purpose watermarking technique to repair image automatically. We use the edge of the original image as the robust watermark and embed it into the lower frequency band as the reference for repairing defected area. We also embedde a fragile watermark into image. By extracting the fragile watermarking, the repair system can detect the defected area automatically. Meanwhile, we utilize the extracted robust watermarking, followed by the texture of object edge, to repair the image block and edge of image. It is difficult to insert two watermarks and to achieve high Peak Signal to Noise Ratio, so we use the Discrete Wavelet Transform and Vector Quantization techniques to minimize the embedded data. According to the experimental results, the embedded watermark is invisible in the test image. When the test image was attacked, this technology can detect the large defected area or complicated defected area and repair it automatically.

參考文獻


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[5] John F. Canny. “A computational approach to edge detection,” IEEE
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