TFT-LCD面板之瑕疵(mura defects)，一般泛指LCM所顯示的均勻影像，具有局部低對比度與不均勻亮度性質。本文利用離散餘弦轉換(DCT)與離散小波轉換(DWT)的方法，成功擷取出模擬blob-mura與實際mura特徵瑕疵。DWT法採用對稱9/7 tap Daubechies小波，偵測對象以小面積mura瑕疵為主，並且有效濾除彩色濾光片的規則條紋結構。而DCT主要偵測對象為大面積亮度不均勻的對象，對於小面積的mura則無法有效檢測出來。

Mura defects in LCM panel of TFT-LCD have the properties of local low contrast and luminance variation without a clear contour on a uniformly produced surface. This thesis proposes two methods which are discrete cosine transform (DCT) and discrete wavelet transform (DWT). These methods successfully detect simulated blob-mura and real mura defects. The DWT method is based on symmetrical 9/7 tap Daubechies coefficients that is superior for filtering the regular structure of color filter and small area defects. DCT method is better for detecting luminance variation in large area defects and poor for small ones.

[1] W. K. Pratt, S. S. Sawkar, and K. O'Reilly, "Automatic blemish detection in liquid crystal flat panel displays," IS&T/SPIE Symposium on Electronic Imaging: Science and Technology, 1998.
[2] Y. Mori, K. Tanahashi, and S. Tsuji, "Quantitative evaluation of “mura” in liquid crystal displays," Optical Engineering, vol. 43, p. 2696, 2004.
[3] Y.-H. Tseng, "Automatic Surface Inspection for TFT-LCD Array Panels Using Fourier Reconstruction," in Department of Industrial Engineering and Management. Master: Yuan Ze University, 2003.
[4] C.-Y. Hung, "Automatic Surface Inspection for TFT-LCD Array Panels Using 1D Fourier Reconstruction," in Department of Industrial Engineering and Management. Master: Yuan Ze University, 2004.
[5] C.-C. Kuo, "Development of Automatic TFT-LCD Mura Defect Detection," in Institute of Automation Technology. Master: National Taipei University of Technology, 2006.
[6] C.-C. Chen, "A study of defects of LCD panel with wavelet method," in Department of Electrical Engineering. Master: Yuan Ze University, 2005.
[7] J. S. Ryu, J. H. Oh, J. G. Kim, T. M. Koo, and K. H. Park, "TFT-LCD panel Blob-Mura inspection using the correlation of wavelet coefficients," TENCON 2004. 2004 IEEE Region 10 Conference, 2004.
[8] Y.-C. Song, D.-H. Choi, and K.-H. Park, "Wavelet-based image enhancement for defect detection in thin film transistor liquid crystal display panel," Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers, vol. 45, no. 6 A, pp. 5069-5072, 2006.
[9] S. G. Mallat, "A theory for multiresolution signal decomposition: the waveletrepresentation," Pattern Analysis and Machine Intelligence, IEEE Transactions on, vol. 11, no. 7, pp. 674-693, 1989.
[10] D. S. Taubman and M. W. Marcellin, Jpeg2000: Image Compression Fundamentals, Standards and Practice: Kluwer Academic Pub, 2002.
[11] Y. Meyer, "Principe d’incertitude, bases hilbertiennes et algebres d’operateurs," Seminaire Bourbaki, vol. 662, no. 62, p. 1986, 1985.
[12] M. Antonini, M. Barlaud, P. Mathieu, and I. Daubechies, "Image coding using wavelet transform," Image Processing, IEEE Transactions on, vol. 1, no. 2, pp. 205-220, 1992.
[13] W. Cai and M. Adjouadi, "Minimization of boundary artifacts on scalable image compression using symmetric-extended wavelet transform," Information Technology: Coding and Computing, 2004. Proceedings. ITCC 2004. International Conference on, vol. 1, 2004.
[14] D. L. Donoho and J. M. Johnstone, "Ideal spatial adaptation by wavelet shrinkage," Biometrika, vol. 81, no. 3, p. 425, 1994.
[15] J.-W. Jhou, "Automatic Optical Inspection on Mura defect of TFT-LCD," in Institute of Manufacturing Engineering. Master: National Cheng Kung University, 2006.
[16] SEMI, "Definition of Measurement Index (Semu) for Luminance Mura in FPD Image Quality Inspection," Semiconductor Equipment and Materials International, 2002.