1. Elements of Biomedical Image Processing BMI 731 Winter 2005 Kun Huang Department of Biomedical Informatics Ohio State University

2. -Introduction to imaging processing -Mathematical background -Convolution and Fourier transform -Filtering -Image enhancement -Noise removal -Color correction and color space transform -Feature extraction -Edge, point, line (Hugh transform) -3-D reconstruction -Radon transform

3. -Image Processing : what should be done? -Image restoration and enhancement -Feature extraction -Pattern recognition

4. -Mathematical Background -Convolution -2-D convolution 1724 1815 235 71416 46 132022 101219213 11182529 294 753 618 1x2+8x9+15x4+7x7+14x5 +16x3+13x6+20x1+22x8 =575

5. -Mathematical Background -Fourier transform (FT) -Mathematics -2-D FT

6. -Mathematical Background -Fourier transform (FT) -Fast FT (FFT)

7. -Mathematical Background -Convolution and Fourier transform (FT)

8. -Mathematical Background -Filtering -High-pass filter, low-pass filter, band pass filter -Gradient filters 11 11 11 11 1111 1111

9. -Mathematical Background -Filtering -Wiener filter and deblurring

10. -Image Enhancement -Denoise -Averaging -Median filter 1/9 20543 78322 115189200 43

11. -Image Enhancement -Denoise/restoration From Gonzalez, Woods, and Eddins

12. -Image Enhancement -Color and intensity adjustment -Histogram equalization

13. -Image Enhancement -Color space transform RGB -> HSV, HSL, YCbCr, … R = 64 G = 31 B = 62 R = 125 G = 80 B = 147 H = 199 S = 117 V = 147 H = 214 S = 132 V = 64

14. -Feature Extraction -Region detection – morphology manipulation -Dilate and Erode -Open -Erode  dilate -Small objects are removed -Close -Dilate  Erode -Holes are closed -Skeleton and perimeter

15. -Feature Extraction -Edge detection -Gradients -Canny edge detector -Gaussian smoothing -Gradients -Two thresholds -Thinning 11 11 11 11 1111 1111

16. -Feature Extraction -Point detection -Harris detector x

17. -Feature Extraction -Radon transform -Straight line detection -Hugh transform  y  y

18. -Feature Extraction -Straight line detection -Hugh transform From Gonzalez, Woods, and Eddins

19. -2-D/3-D reconstruction -Radon/inverse radon transforms and backprojection

20. -Reference -Digital Image Processing using Matlab By R.C.Gonzalez, R.E.Woods, and S.L.Eddins Published by Printice-Hall, 2004