快速傅里叶变换FFT下的缺陷检测

Halcom

1. * to detect small texture defects on the surface of plastic items
   
2. * by using the fast fourier transform (FFT)
   
3. dev_update_off ()
   
4. dev_close_window ()
   
5. read_image (Image, 'plastics/plastics_01')
   
6. get_image_size (Image, Width, Height)
   
7. dev_open_window (0, 0, Width, Height, 'black', WindowHandle)
   
8. set_display_font (WindowHandle, 14, 'mono', 'true', 'false')
   
9. dev_set_draw ('margin')
   
10. dev_set_line_width (3)
    
11. dev_set_color ('red')
    
12. * 优化FFT计算速度
    
13. optimize_rft_speed (Width, Height, 'standard')
    
14. * 高斯带通滤波
    
15. Sigma1 := 10.0
    
16. Sigma2 := 3.0
    
17. gen_gauss_filter (GaussFilter1, Sigma1, Sigma1, 0.0, 'none', 'rft', Width, Height)
    
18. gen_gauss_filter (GaussFilter2, Sigma2, Sigma2, 0.0, 'none', 'rft', Width, Height)
    
19. sub_image (GaussFilter1, GaussFilter2, Filter, 1, 0)
    
20. * 循环读取
    
21. NumImages := 11
    
22. for Index := 1 to NumImages by 1
    
23.     * 读入图像
    
24.     read_image (Image, 'plastics/plastics_' + Index 02')
    
25.     rgb1_to_gray (Image, Image)
    
26.     * Perform the convolution in the frequency domain
    
27.     rft_generic (Image, ImageFFT, 'to_freq', 'none', 'complex', Width)
    
28.     convol_fft (ImageFFT, Filter, ImageConvol)
    
29.     rft_generic (ImageConvol, ImageFiltered, 'from_freq', 'n', 'real', Width)
    
30.     * 对滤波后图像进行处理
    
31.     * 在10x10掩膜内，遍历计算maxGrayValue-minGrayValue
    
32.     gray_range_rect (ImageFiltered, ImageResult, 10, 10)
    
33.     min_max_gray (ImageResult, ImageResult, 0, Min, Max, Range)
    
34.     threshold (ImageResult, RegionDynThresh, max([5.55,Max * 0.8]), 255)
    
35.     * 连通域检测
    
36.     connection (RegionDynThresh, ConnectedRegions)
    
37.     select_shape (ConnectedRegions, SelectedRegions, 'area', 'and', 4, 99999)
    
38.     union1 (SelectedRegions, RegionUnion)
    
39.     * 形态学闭运算
    
40.     closing_circle (RegionUnion, RegionClosing, 10)
    
41.     connection (RegionClosing, ConnectedRegions1)
    
42.     select_shape (ConnectedRegions1, SelectedRegions1, 'area', 'and', 10, 99999)
    
43.     area_center (SelectedRegions1, Area, Row, Column)
    
44.    
    
45.     * 显示最终的结果
    
46.     dev_display (Image)
    
47.     Number := |Area|
    
48.     if (Number)
    
49.         gen_circle_contour_xld (ContCircle, Row, Column, gen_tuple_const(Number,30), gen_tuple_const(Number,0), gen_tuple_const(Number,rad(360)), 'positive', 1)
    
50.         ResultMessage := ['Not OK',Number + ' defect(s) found']
    
51.         Color := ['red','black']
    
52.         dev_display (ContCircle)
    
53.     else
    
54.         ResultMessage := 'OK'
    
55.         Color := 'forest green'
    
56.     endif
    
57.     disp_message (WindowHandle, ResultMessage, 'window', 12, 12, Color, 'true')
    
58.     if (Index != NumImages)
    
59.         disp_continue_message (WindowHandle, 'black', 'true')
    
60.         stop ()
    
61.     endif
    
62. endfor

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