臺灣博碩士論文加值系統

高動態範圍影像是一種能將真實場景所產生的亮度做完整保存的影像格式。但其影像格式所需要的儲存空間較為龐大，在傳輸上也較為困難，所以目前市面上的數位相機大多以低動態範圍影像做為影像的儲存格式，其好處是影像檔案所需儲存空間較小。但低動態範圍影像並不能將真實世界的亮度完整保存，所以若能將兩種影像格式的特性加以融合，將有助於高動態範圍影像的應用與發展。目前有許多學者也針對這兩種格式的特性做研究，並提出許多高動態範圍影像的融合方法，藉此以低動態範圍影像模擬出高動態範圍影像效果的高品質影像。

本論文提出使用色調再生之多重曝光影像融合，以數張低動態範圍影像來融合出具高動態範圍影像效果之低動態範圍影像。一開始先輸入的多張相同場景不同曝光程度的影像，挑選其影像序列當中細節表現較佳的部分，加以拼湊出一張影像。挑選好區塊以後，對當中較不自然的色彩做混合的動作，透過色調再生演算法中的YCbCr色彩空間轉換，將其色彩混合影像以及亮度平均值影像融合，消除影像中較為不自然的部分，藉此融合出具高動態範圍影像效果之影像。

The high dynamic range (HDR) imaging is a technique that allows saving intact luminance information of an image in real scene. The main disadvantage of the HDR imaging is that it requires huge memory storage and may cause difficulties in transmission. Thus, most digital cameras in current market use low dynamic range (LDR) imaging technique for image storage. However, the LDR image lacks the ability to perform intact luminance information of an image in real scene. Many researchers have developed techniques on merging several LDR images to produce a new LDR image with the quality of a HDR image.

This paper proposes to fuse multiple exposure low dynamic range (LDR) images by using tone reproduction method. The produced image is another LDR image which has the visual quality of a high dynamic range (HDR) image. The input is a series of multiple exposure images of the same scene. Each input image is equally segmented to several blocks. For each block, the one with the best visual effect is selected from one of these input images to integrate a new image. A tone reproduction algorithm is used to fuse these selected blocks to form an image with the visual effect of a HDR image.

中文摘要..i
英文摘要..ii
誌謝......iii
目錄......iv
圖目錄.........vi
符號說明........ix

第一章 緒論..........................1
1.1 研究背景....................1
1.2 研究目的....................5
1.3 系統架構....................7
1.4 論文架構....................9

第二章 相關背景......................10
2.1 適應性對數映射演算法........10
2.2 多曝光影像融合演算法........13
2.3 曝光影像融合演算法..........15
2.4 YCbCr色彩空間...............18

第三章 研究方法與系統架構.............19
3.1 YCbCr 色彩空間轉換...........19
3.2 亮度平均值計算...............23
3.3 挑選影像中較好區塊...........25
3.4 多重曝光影像融合.............27

第四章 實驗結果.......................30
4.1 實驗相關環境及設備...........30
4.2 實驗結果呈現.................30
4.3 高動態範圍影像演算法上與其他方法做比較..39

第五章 結論與未來展望.................41

參考文獻..............................42

個人簡歷..............................43

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