simple license plate recognition

Graph

• code
• results
• • positioning location results
  • recognition results

  original

  

  code

  dev_close_window ()
  *车牌定位及倾斜旋转
  read_image (Car, 'E:/Halcon_Learn/car.jpg')
  get_image_size (Car, Width, Height)
  dev_open_window (0, 0, Width, Height, 'black', WindowHandle)
  dev_set_color ('green')
  dev_set_line_width (3)
  decompose3 (Car, Image1, Image2, Image3)
  threshold (Image1, Regions, 0, 31)
  connection (Regions, ConnectedRegions)
  select_shape (ConnectedRegions, SelectedRegions, 'area', 'and', 4636.72, 5508.59)
  dilation_circle (SelectedRegions, RegionDilation, 3.5)
  erosion_circle (RegionDilation, RegionErosion, 3.5)
  fill_up (RegionErosion, RegionFillUp)
  orientation_region (RegionFillUp, Phi)
  area_center (RegionFillUp, Area, Row, Column)
  vector_angle_to_rigid (Row, Column, Phi, Row, Column, rad(180), HomMat2D)
  affine_trans_image (Car, ImageAffineTrans, HomMat2D, 'constant', 'false')
  affine_trans_region (RegionFillUp, RegionAffineTrans, HomMat2D, 'nearest_neighbor')
  reduce_domain (ImageAffineTrans, RegionAffineTrans, ImageReduced)
  *显示定位车牌
  dev_display (ImageAffineTrans)
  overpaint_region (ImageAffineTrans, RegionAffineTrans, [0,255,0], 'margin')
  dump_window_image (Image_define, WindowHandle)
  write_image (Image_define, 'jpg', 0, 'E:/Halcon_Learn/car_define')
  stop ()
  *字符分割
  rgb1_to_gray (ImageReduced, GrayImage)
  invert_image (GrayImage, ImageInvert)
  threshold (GrayImage, Regions1, 61, 126)
  connection (Regions1, ConnectedRegions1)
  select_shape (ConnectedRegions1, SelectedRegions1, ['area','height'], 'and', [219,31.607], [321.78,40.742])
  sort_region (SelectedRegions1, SortedRegions, 'character', 'true', 'row')
  
  *字符识别
  read_ocr_class_mlp ('Industrial_0-9A-Z_NoRej.omc', OCRHandle)
  do_ocr_multi_class_mlp (SortedRegions, ImageInvert, OCRHandle, Class, Confidence)
  
  *显示
  smallest_rectangle1 (SortedRegions, Row1, Column1, Row2, Column2)
  count_obj (SortedRegions, Number)
  dev_display (Car)
  for i := 1 to Number by 1
     * disp_message (WindowHandle, Class[i-1], 'window', Row2[i-1], Column1[i-1], 'red', 'false')
       set_tposition (WindowHandle, Row2[i-1], Column1[i-1])
       write_string (WindowHandle, Class[i-1])
  endfor
  
  dump_window_image (Image, WindowHandle)
  write_image (Image, 'jpg', 0,'E:/Halcon_Learn/car_result')
  

  Results the

  positioning result

  

  recognition result