Halcon标定测量有误差，求原因

用100mm标定文件进行标定，标定完成后，实际测量7.1cm,相机测量结果为7.5cm，误差0.4cm,求原因。。。以下为标定步骤，求大神指点


标定程序：

1. * Image Acquisition 01: Code generated by Image Acquisition 01
   
2. open_framegrabber ('DirectShow', 1, 1, 0, 0, 0, 0, 'default', 8, 'rgb', -1, 'false', '[1] RGB24 (2048x1536)', '[1]', 0, -1, AcqHandle)
   
3. grab_image_start (AcqHandle, -1)
   
4. grab_image_async (Image, AcqHandle, -1)
   
5. 
   
6. * Calibration 01: Code generated by Calibration 01
   
7. read_cam_par ('G:/halcon/halcon例程/标定测量/图片及参数（新）/12-27-02/参数.cal', CameraParameters)
   
8. read_pose ('G:/halcon/halcon例程/标定测量/图片及参数（新）/12-27-02/位姿.dat', CameraPose)
   
9. stop ()
   
10. 
    
11. * Calibration 01: Sample code generated by Calibration 01
    
12. * Calibration 01: For demonstration purposes, we use the calibration
    
13. * Calibration 01: plate itself as sample object.
    
14. * Calibration 01: Therefore, please take another calibration plate image
    
15. stop ()
    
16. grab_image_async (Image, AcqHandle, -1)
    
17. close_framegrabber (AcqHandle)
    
18. * Calibration 01: Extract plate data from the image
    
19. TmpCtrl_PlateDescription := 'G:/halcon/halcon例程/制作标定板/caltab.descr'
    
20. TmpCtrl_FindCalObjParNames := ['gap_tolerance','alpha','skip_find_caltab']
    
21. TmpCtrl_FindCalObjParValues := [1,1,'false']
    
22. * Calibration 01: Create calibration model for managing calibration data
    
23. create_calib_data ('calibration_object', 1, 1, CalibHandle)
    
24. set_calib_data_cam_param (CalibHandle, 0, [], CameraParameters)
    
25. set_calib_data_calib_object (CalibHandle, 0, TmpCtrl_PlateDescription)
    
26. find_calib_object (Image, CalibHandle, 0, 0, 0, TmpCtrl_FindCalObjParNames, TmpCtrl_FindCalObjParValues)
    
27. get_calib_data_observ_points (CalibHandle, 0, 0, 0, TmpCtrl_MarkRows, TmpCtrl_MarkColumns, TmpCtrl_Ind, CameraPose)
    
28. * Calibration 01: Using the calibration plate as test object, the marks actually
    
29. * Calibration 01: lie above the corrected measurement plane. Therefore, we 'uncorrect'
    
30. * Calibration 01: the plane of measurement by the plate thickness here.
    
31. set_origin_pose (CameraPose, 0.0, 0.0, 0.001, CameraPose)
    
32. * Calibration 01: **********************************************************
    
33. * Calibration 01: Sample Task: Transform measurements into world coordinates
    
34. * Calibration 01: **********************************************************
    
35. * Calibration 01: First, obtain the image coordinates of some points of interest
    
36. * Calibration 01: lying in the reference plane. Here, we simply take the first
    
37. * Calibration 01: two mark center points of the plate
    
38. TmpCtrl_ImageRows := [TmpCtrl_MarkRows[0], TmpCtrl_MarkRows[6]]
    
39. TmpCtrl_ImageColumns := [TmpCtrl_MarkColumns[0], TmpCtrl_MarkColumns[6]]
    
40. * Calibration 01: A line between the two points, just for visualization
    
41. gen_contour_polygon_xld (TmpObj_ImageContour, TmpCtrl_ImageRows, TmpCtrl_ImageColumns)
    
42. * Calibration 01: Convert image coordinate to world coordinates (using [mm])
    
43. * Calibration 01: The Z coordinates will be 0 by definition (on reference plane)
    
44. image_points_to_world_plane (CameraParameters, CameraPose, TmpCtrl_ImageRows, TmpCtrl_ImageColumns, 'mm', TmpCtrl_WorldX, TmpCtrl_WorldY)
    
45. * Calibration 01: Determine the distance in world coordinate [mm]
    
46. distance_pp (TmpCtrl_WorldY[0], TmpCtrl_WorldX[0], TmpCtrl_WorldY[1], TmpCtrl_WorldX[1], TmpCtrl_Distance)
    
47. stop ()
    
48. 
    

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厚度  ？

你这个标定虽然单个像元基本准确，但是你的颈向畸变系数kappa 太大，你的宽度和高度对应的中心距离有4个和146像素偏差，你看看你的距离是多少像素，按照标定后3.2um算！感觉你的图像畸变有点明显，没有矫正？

amnoone 发表于 2018-12-27 21:21
厚度  ？

图像畸变是不是在使用image_to_world_palne的时候就已经矫正了，因为这个算子需要输入相机的内外参呀，自己的理解不知道对不对

焦距你填写参数的4mm，标定完是7.5mm，如果参数没问题，看看标定后计算的像素当量值，再计算实际尺寸，误差大肯定是标定有问题

我猜测这焦距参数填错了，你再确认下

请问楼主这个解决了吗？怎么解决的，遇到同问题

你的KAP出来的数据太大，还有镜头的焦距可能填写不对，标定后不会变化如此大；

你那标定板是张纸来着，厚度应该填0

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