1. 1 Source: Journal of Chemical Information & Computer Sciences, 2003, vol.43, pp.978-986 Authors: K. Kaczmarek, B. Walczak, S. de Jong, and B. G. M. Vandeginste Speaker: Shu-Fen Chiou( 邱淑芬 ) Date: 2005/07/22 Matching 2D Gel Electrophoresis Images

2. 2 Outline Introduction Method Experimental results Conclusion Comment

3. 3 Introduction Automatic alignment (matching) of two- dimensional gel electrophoresis images is of primary interest in the field of proteomics.

4. 4 Method Transformation of Coordinates

5. 5 Method Use bilinear transform: a = [a 0,a 1, a 2, a 3 ] = [0, 0, 1, 0] b = [b 0,b 1, b 2, b 3 ] = [1, 1, 0, 0] x2* = 0+0  10+1  10+(0  10  10) = 10 y2* = 1+1  10+0  10+(0  10  10) = 11 10,10 Image 1Image 2 10,11

6. 6 Method Interpolation pixel value 10,10 pixel value=125 Image 1Image 2 10.5,11.5 11,11 10,1110,12 11,12 Pixel value = ((10,11)+(10,12)+(11,11)+(11,12)) / 4 = (128+115+118+120) / 4 = 120

7. 7 Method Calculate similarity (difference)

8. 8 Fuzzy Alignment of Images Features

9. 9 Method Visualization of Matched Images

10. 10 Experimental results

11. 11 Experimental results

12. 12 Experimental results

13. 13 Experimental results

14. 14 Experimental results

15. 15 Conclusions The presented method of gel image matching allows efficient automated matching of two- dimensional gel electrophoresis images. Final goodness of a fit depends on a type of transform also and on the interpolation method used.

16. 16 Comment 使用內插法重新表現像素值，將使得原始像素 失真。 利用區塊比對，比較相似度。