臺灣博碩士論文加值系統

數位影像相關法是一種非接觸、非破壞性的光學量測方法，其原理是藉由比對第二張影像中各像素與第一張影像(參考影像)中固定之參考像素點之相關性，從而由第二張影像中找出與第一張影像參考像素點有著最大相關性之像素點，此點即為此參考像素點之於第二張影像中之對應點，於統計學中有數種方法用以計算相關係數，應用於數位影像相關法中最常見使用皮爾森積差相關係數來進行相關性匹配之運算。
本研究藉由取得物體表面變形前後之影像，並將變形前影像定為參考影像，利用數位影像相關法以尋找參考影像中各像素於變形後影像中之整數對應點，並藉由一個簡單的位移方程式及亮度轉換模型配合牛頓法理論進行此位移方程式之優化，透過迭代運算進而求得物體表面於變形後位移及應變之次像素部分，再將計算出之位移及應變藉由濾波處理使之平滑化，進而獲取物體表面於變形後之全域位移場及應變場。

Digital image correlation method is a non-contact, non-destructive optical measuring method, the principle is the second image by comparing each pixel with the first image (reference image) in the fixed point of reference pixel correlation to find images from the second image with the first reference pixel has a maximum correlation of the pixels, the point that this reference in the second pixel of the image of the corresponding points in the statistics there are several kinds of method used to calculate the correlation coefficient, used in digital image correlation method is the most common use of Pearson''s correlation coefficient for correlation matching of operations.
In this study, obtained by deformation of the surface before and after images, and image distortion as a reference image before using the digital image correlation method to find the reference image of each pixel in the deformed image of the integer corresponding to the point, and by a simple displacement equation and the brightness of the transformation model with the theory of the Newton equation of motion optimization, and then obtained through iteration after the surface displacement and strain in the deformation of sub-pixel part, and then calculate the displacement and strain by filtering the of smoothing, and then obtain the deformed surface in the global displacement field and strain field.

第一章 緒論 1
1.1 前言 1
1.2 文獻回顧 1
1.3研究目的與動機 3
第二章 基礎理論 4
2.1數位影像(Digital Image) 4
2.1.1彩色影像(Color Image) 5
2.1.2二值化影像(Binary Image) 5
2.1.3灰階影像(Gray-Level Image) 6
2.2 相關係數(Correlation Coefficient) 7
2.3 數位影像相關法(Digital Image Correlation) 8
2.4 次像素註冊 10
2.5 影像內插 10
2.5.1 最鄰近點內插(Nearest Neighbor Interpolation) 11
2.5.2 雙線性內插(Bilinear Interpolation) 12
2.5.3 雙立方內插(Bicubic Interpolation) 13
2.6 牛頓法(Newton’s Method) 15
2.7 平滑濾波器 17
2.7.1 平均濾波器 17
2.7.2 中值濾波器 18
2.7.3 高斯濾波器 18
第三章 實驗流程與方法 19
3.1 實驗流程圖 19
3.2 影像亮度轉換模型 20
3.3 位移方程式 21
3.4 相關性運算 22
3.5子區中心次像素位移及子區位移梯度 25
3.6 應變場平滑化 28
3.6.1 對應變場進行平均濾波 28
3.6.2 逐點最小平方法(Pointwise Least Square Method) 28
3.6.3 對位移場進行平均濾波再使用PLS方法 30
第四章 實驗模擬與實驗結果 31
4.1 實驗模擬 31
4-2 實驗結果 41
第五章 結論與未來展望 45
5.1 結論 45
5.2 未來展望 45
參考文獻 46

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