halcon代码：

read_image (Audi2, 'audi2')fill_interlace (Audi2, ImageFilled, 'odd')dev_set_color('green')threshold (ImageFilled, Region, 0, 90)connection (Region, ConnectedRegions)select_shape (ConnectedRegions, SelectedRegions, 'width', 'and', 30, 70)select_shape (SelectedRegions, Letters, 'height', 'and', 60, 110)*dev_clear_window ()*dev_set_colored (12)*dev_display (ImageFilled)*dev_display (Letters)   read_ocr_class_mlp('Industrial_0-9A-Z.omc',OCRHandle) do_ocr_multi_class_mlp(Letters,Audi2,OCRHandle, Class, Confidence)  *显示识别的结果area_center(Letters, Area, Row, Column)for Index := 0 to 6 by 1     disp_message(3600, Class[Index], 'window', Row[Index], Column[Index], 'black', 'true') endfor

初始图片：

处理后的图片，将车牌所在的区域识别出来：

显示输出结果：

*Class[0]--class[6]分别为GAPV329

area_center(Letters, Area, Row, Column)for Index := 0 to 6 by 1     disp_message(3600, Class[Index], 'window', Row[Index], Column[Index], 'black', 'true') endfor