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Elements of Biomedical Image ProcessingBMI 731 Winter 2005
Kun HuangDepartment of Biomedical Informatics
Ohio State University
- 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
- Image Processing : what should be done?- Image restoration and enhancement- Feature extraction- Pattern recognition
- Mathematical Background- Convolution
- 2-D convolution
17 241 8 15
23 57 14 16
4 613 20 22
10 12 19 21 3
11 18 25 2 9
2 9 4
7 5 3
6 1 8
1x2+8x9+15x4+7x7+14x5+16x3+13x6+20x1+22x8=575
- Mathematical Background- Fourier transform (FT)
- Mathematics
- 2-D FT
- Mathematical Background- Fourier transform (FT)
- Fast FT (FFT)
- Mathematical Background- Convolution and Fourier transform (FT)
- Mathematical Background- Filtering
- High-pass filter, low-pass filter, band pass filter
- Gradient filters
1 1 -1 -1
1 1 -1 -1
1 1 -1 -1
1 1 -1 -1
-1 -1 -1 -1
-1 -1 -1 -1
1 1 1 1
1 1 1 1
- Mathematical Background- Filtering
- Wiener filter and deblurring
- Image Enhancement- Denoise
- Averaging
- Median filter
1/9 1/9 1/9
1/9 1/9 1/9
1/9 1/9 1/9
20 5 43
78 3 22
115 189 200
43
- Image Enhancement- Denoise/restoration
From Gonzalez, Woods, and Eddins
- Image Enhancement- Color and intensity adjustment
- Histogram equalization
- Image Enhancement- Color space transform
RGB -> HSV, HSL, YCbCr, …
R = 64G = 31B = 62
R = 125G = 80B = 147
H = 199S = 117V = 147
H = 214S = 132V = 64
- 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
- Feature Extraction- Edge detection
- Gradients
- Canny edge detector- Gaussian smoothing- Gradients- Two thresholds- Thinning
1 1 -1 -1
1 1 -1 -1
1 1 -1 -1
1 1 -1 -1
-1 -1 -1 -1
-1 -1 -1 -1
1 1 1 1
1 1 1 1
- Feature Extraction- Point detection
- Harris detector
x
- Feature Extraction- Radon transform
- Straight line detection- Hugh transform
y
y
- Feature Extraction- Straight line detection
- Hugh transform
From Gonzalez, Woods, and Eddins
- 2-D/3-D reconstruction- Radon/inverse radon transforms and
backprojection
- Reference- Digital Image Processing using Matlab
By R.C.Gonzalez, R.E.Woods, and S.L.EddinsPublished by Printice-Hall, 2004