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http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/40662
Title: | 階層式降雜訊 Hierarchical Noise Reduction |
Authors: | Yen-Chun Wang 王彥鈞 |
Advisor: | 傅楸善(Chiou-Shann Fuh) |
Keyword: | 影像,去雜訊, noise reduction,denoise,image, |
Publication Year : | 2008 |
Degree: | 碩士 |
Abstract: | 在此篇論文當中,我們將介紹一個階層式降雜訊的演算法,而此演算法能夠有效地消除雜訊並且同時保留影像的細節。
這個階層式的方法首先會將一張影像轉換為向下取樣的四張圖片,其向下取樣的程度皆不同,因此這四張不同大小的圖片粗略而言分別隱含有原始圖片中不同頻率的資訊。因此我們不必將原始影像轉換到頻率域即可對圖片的不同頻率做不同的處理。 接下來,我們會在這四張子圖中分別找出影像的邊,也就是一般所謂的影像細節,並且再對細節及非細節處分別做不同的平滑處理。 當所有操作在這四張子圖都完成時,我們會將它們重新合併而成為一張消除完雜訊的影像。 In this thesis, we introduce a hierarchical noise reduction algorithm which can reduce the noise and preserve the details of the images. This hierarchical method converts an image into a set of four downscaled images which contain information of different frequency in original image. Hence we can process the image in different frequency layers without transferring to frequency domain. Afterwards, we find edge pixels in each sub-image and apply different smoothing methods to edge pixels and non-edge pixels. After handling all four layers of original image, four sub-images are combined to produce a de-noised image. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/40662 |
Fulltext Rights: | 有償授權 |
Appears in Collections: | 資訊工程學系 |
Files in This Item:
File | Size | Format | |
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ntu-97-1.pdf Restricted Access | 3.33 MB | Adobe PDF |
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