Title page for 985202047


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Student Number 985202047
Author Yi-yi Yeh(葉宜益)
Author's Email Address No Public.
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Department Computer Science and Information Engineering
Year 2010
Semester 2
Degree Master
Type of Document Master's Thesis
Language zh-TW.Big5 Chinese
Title A modified EMD method using the local adaptation strategy and its application to non-uniform illumination removal
Date of Defense 2011-07-25
Page Count 87
Keyword
  • AEMD
  • color image
  • EMD
  • least-squares approximation
  • non-uniform illumination
  • Abstract  In this thesis, we focus on solving the problem of uneven light effect on document images. A method based on EMD theorem is proposed to estimate and rectify the light-field. Our proposed method does not need to extract the IMF signal and only need to consider the max-envelope instead of all envelopes and residue function in EMD to obtain the light-field distributions of images. Our system consists of three parts including max-envelope calculation, light-field distribution adjustment, and signal scale adjustment.
     In the first part, we first use fast method, least-squares approximation, to find max-envelope form input signal scale via one dimensional way. In the second part, we observe the distributions of max-envelope and signal to find the max differential point between light-fields as the cut points. Then, segment the signal by the cut points and calculate local max-envelopes to obtain closer light-field distribution of original signal. In the third part, we will set the contrast value depending on light-field intensity and enhance the gray scale signal. The contrast value will be fixed if it is an over-exposure signal. Last, enhance gray scale signal by contrast value and finally adjust the enhanced gray scale.
     Experimental results show that our method exhibits good outcome about removing over-exposure, shadow, reflection and back-light effects on document images. Besides, the execution time is much faster than EMD and the recognition result can achieve the same efficiency of EMD method.
     As to the color image uneven light-field effect, we calculate the max-envelope by “Triangle Linear Interpolation”, and adjust the value-element (V of HSV color system) to conserve the property of continuous color information. Experimental results demonstrate that our proposed method performs well on color images too.
    Table of Content 摘要.........I
    Abstract....II
    目錄.........III
    附圖目錄......V
    附表目錄......VIII
    第一章 緒論......1
    1.1 研究動機......1
    1.1.1 應用取像......1
    1.1.2 相機取像之文字辨識......2
    1.2 文獻探討......3
    1.3 系統架構......5
    1.4 論文架構......7
    第二章 經驗模態分解法(EMD)......8
    2.1 EMD介紹......8
    2.2 EMD演算法......10
    2.3 EMD範例......14
    第三章 可適性EMD(Adaptive EMD)......22
    3.1 影像光場與EMD包絡線關係......22
    3.2 上包絡線逼近與光場分析......26
    3.2.1 最小平方近似法..........26
    3.2.2 同一光場分布的包絡線分析......29
    3.2.3 不同光場分布的分析......31
    3.3 AEMD......33
    3.3.1 偏離區間與分段點......33
    3.3.2 分段點區域與分段點數......35
    3.3.3 AEMD流程......39
    3.4 ABEMD......46
    3.4.1 三角形內插法(Triangle Linear Interpolation)......46
    3.4.2 上包絡面調整......47
    第四章 AEMD在光場矯正上的應用......49
    4.1 曝光過度文字影像的判斷與對比度選取......50
    4.2 非曝光過度對比度選取......51
    4.3 文字影像光影矯正......52
    4.3.1 強化灰階值對比......52
    4.3.2 光影去除......55
    4.4 彩色影像光影去除......56
    第五章 實驗結果......58
    5.1 文件影像不同光影影響實驗結果......58
    5.1.1 實驗設備與環境......58
    5.1.2 不同的文件影像光影去除......58
    5.1.3 辨識率與時間比較......68
    5.2 實驗五:彩色影像......70
    第六章 結論與未來工作......73
    參考文獻......74
    Reference [1] Norden E. Huang ,"The Empirical Mode Decomposition and The Hilbert Spectrum for Nonlinear and Non-stationary Time Series Analysis , "NASA.(manuscript) , 1996.
    [2] Norden E. Heng Shen , Steven R. Long , Manli C. Wu , Hsing H. Shih , Quanan Zheng , Nai-Chyuan. Yen , Chi Chao Tung , and Henry H. Liu , "The Empirical Mode Decomposition and The Hilbert Spectrum for Nonlinear and Non-stationary Time Series Analysis ," Proc. R. Sec. London A , The Royal Society , pp. 903-995, 1998.
    [3] Soo-Chang Pei and Feng-Ju Chang,"Effective color constancy method under uniform of non-uniform illuminant",23th Conf. in Computer Vision, Graphics and Image Processing(CVGIP), 2010
    [4] Soo-Chang Pei and Mary Tzeng "Uneven Illumination Removal and Image Enhancement Using Empirical Mode Decomposition," 20th Conf. in Computer Vision, Graphics and Image Processing(CVGIP), 2007.
    [5] Hany Farid and Edward H. Adelson,"Separating Reflections and Lighting Using Independent Components Analysis," in IEEE Computer Society Conf. Computer Vision and Pattern Recognition, vol. 1, June 23-25 , pp. 262-267. 1999
    [6] Yen-Wei Chen,Gang Xu and Masaki Yamazaki , " Separation of Reflection Components by Kernel Independent Component Analysis" in 18th Int. Conf. Pattern Recognition(ICPR), vol. 3, pp. 194-197 , 2006
    [7] Sei-Wang Chen,Yun-Chung Chung ,Shyang-Lih Chang and Jung-Ming Wang, "Interference Reflection Separation from a Single Image" Applications of Computer Vision (WACV),pp.001-006 ,2009
    [8] Chien-Hsing Choua, Wen-Hsiung Linb and Fu Changb , " A binarization method with learning-built rules for document images produced by cameras ",Pattern Recognition ,Volume 43, Issue 4, Pages 1518-1530 , April 2010
    [9] Shijian Lu, Chew Lim Tan and Bolan Su "Document image binarization using background estimation and stroke edges", International Journal on Document Analysis and Recognition , Volume 13 Issue 4, December 2010
    [10] Jean Claude Nunes, Yasmina Bouaoune, Eric Delechelle, Oumar Niang, Philippe Bunel, "Image Analysis by Bidimensional Empirical Mode Decomposition", Image and Vision Computing, vol. 21, pp.1019- 1026, 2003.
    [11] Shuen-De Wu , Liang-Jung Chen , Chiu-Wen Wu,Guan-Yu Chen and Chia-Chi Lin , "Improving the computational efficiency of empirical mode decomposition algorithm by down sampling ", International Journal of Advanced Information Technologies (IJAIT) , Vol. 4 , No. 2 , 2010。
    [12] 吳順德,陳思予,陳虹伯“經驗模態分解法之研究趨勢探討與問題分析” ,臺北科技大學學報, No.42-1, 2009。
    [13] 吳政憲,「希爾伯特阻尼頻譜於高樓損傷評估之應用」,國立中央大學土木工程研究所,碩士論文,民國 90 年
    [14] Ron Larson and Bruce H. Edwards, Elementary Linear Algebra 4th ed., Houghton Mifflin Company, 2000.
    [15] Marc Ebner, "Color constancy base on local space average color" ,Machine Vision and Applications, vol. 11, No. 5, July, 2009.
    [16] Joost van de Weijer, Theo Gevers, and Arjan Gijsenij, "Edge-Based Color Constancy" ,IEEE Trans. on image processing, Vol. 16, No. 9, September 2007.
    Advisor
  • Kuo-chin Fan(范國清)
  • Files
  • 985202047.pdf
  • approve in 3 years
    Date of Submission 2011-08-16

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