halcon学习笔记——摄像机标定

   1: * Attention:

   2: * This program reads the interior camera parameters from the file

   3: * ‘camera_parameters.dat‘, which, e.g., could be generated by the program

   4: * ‘camera_calibration_interior.hdev‘

   5: *

   6: ImgPath := ‘3d_machine_vision/calib/‘

   7: dev_close_window ()

   8: dev_open_window (0, 0, 652, 494, ‘black‘, WindowHandle)

   9: dev_update_off ()

  10: dev_set_draw (‘margin‘)

  11: dev_set_line_width (1)

  12: set_display_font (WindowHandle, 14, ‘courier‘, ‘true‘, ‘false‘)

  13: * Read the interior camera parameters from file

  14: read_cam_par (‘camera_parameters.dat‘, CamParam)

  15: *

  16: * Determine the exterior camera parameters and world coodinates from image points

  17: *

  18: * The exterior camera parameters can be determined from an image, where the

  19: * calibration plate is positioned directly on the measurement plane

  20: read_image (Image, ImgPath+‘calib_11‘)

  21: dev_display (Image)

  22: * parameter settings for find_caltab and find_marks_and_pose

  23: SizeGauss := 3

  24: MarkThresh := 200

  25: MinDiamMarks := 10

  26: StartThresh := 128

  27: DeltaThresh := 10

  28: MinThresh := 18

  29: Alpha := 0.9

  30: MinContLength := 15

  31: MaxDiamMarks := 100

  32: CaltabName := ‘caltab_30mm.descr‘

  33: find_caltab (Image, Caltab, CaltabName, SizeGauss, MarkThresh, MinDiamMarks)

  34: dev_set_color (‘green‘)

  35: dev_display (Caltab)

  36: * Here, the final camera parameters are already known and can be used instead of the starting values

  37: * used in the program ‘camera_calibration_interior.hdev‘

  38: find_marks_and_pose (Image, Caltab, CaltabName, CamParam, StartThresh, DeltaThresh, MinThresh, Alpha, MinContLength, MaxDiamMarks, RCoord, CCoord, PoseForCalibrationPlate)

  39: dev_set_color (‘red‘)

  40: disp_caltab (WindowHandle, CaltabName, CamParam, PoseForCalibrationPlate, 1)

  41: dev_set_line_width (3)

  42: disp_circle (WindowHandle, RCoord, CCoord, gen_tuple_const(|RCoord|,1.5))

  43: * caltab_points (CaltabName, X, Y, Z)

  44: * camera_calibration (X, Y, Z, RCoord, CCoord, CamParam, InitialPoseForCalibrationPlate, ‘pose‘, CamParamUnchanged, FinalPoseFromCalibrationPlate, Errors)

  45: * To take the thickness of the calibration plate into account, the z-value

  46: * of the origin given by the camera pose has to be translated by the

  47: * thickness of the calibration plate.

  48: * Deactivate the following line if you do not want to add the correction.

  49: set_origin_pose (PoseForCalibrationPlate, 0, 0, 0.00075, PoseForCalibrationPlate)

  50: disp_continue_message (WindowHandle, ‘black‘, ‘true‘)

  51: stop ()

  52: * Alternatively, the exterior camera parameters can  be determined from

  53: * at least three point correspondances between the WCS and the pixel coordinate system

  54: read_image (Image, ImgPath+‘caliper_01‘)

  55: dev_display (Image)

  56: * Set the world coordinates of three points on the rule

  57: X := [0,50,100,80]

  58: Y := [5,0,5,0]

  59: Z := [0,0,0,0]

  60: * Set the respective image plane coordinates of the three points

  61: RCoord := [414,227,85,128]

  62: CCoord := [119,318,550,448]

  63: *

  64: disp_cross (WindowHandle, RCoord, CCoord, 6, 0)

  65: * create_pose (-50, 25, 400, 0, 0, -30, ‘Rp+T‘, ‘gba‘, ‘point‘, InitialPose)

  66: vector_to_pose (X, Y, Z, RCoord, CCoord, CamParam, ‘iterative‘, ‘error‘, FinalPose, Errors)

  67: * camera_calibration (X, Y, Z, RCoord, CCoord, CamParam, InitialPose, ‘pose‘, CamParamUnchanged, FinalPose, Errors)

  68: write_pose (FinalPose, ‘pose_from_three_points.dat‘)

  69: * Now, transform a point measured interactively into the WCS

  70: dev_update_window (‘on‘)

  71: dev_display (Image)

  72: while (1)

  73:     disp_message (WindowHandle, ‘Measure one point: left mouse button‘, ‘window‘, 12, 12, ‘red‘, ‘false‘)

  74:     disp_message (WindowHandle, ‘Exit measure mode: right mouse button‘, ‘window‘, 36, 12, ‘red‘, ‘false‘)

  75:     get_mbutton (WindowHandle, Row, Column, Button)

  76:     if (Button = 4)

  77:         break

  78:     endif

  79:     dev_display (Image)

  80:     dev_set_color (‘green‘)

  81:     disp_cross (WindowHandle, Row, Column, 6, 0)

  82:     image_points_to_world_plane (CamParam, FinalPose, Row, Column, 1, X1, Y1)

  83:     disp_message (WindowHandle, ‘X = ‘+X1, ‘window‘, 320, 400, ‘red‘, ‘false‘)

  84:     disp_message (WindowHandle, ‘Y = ‘+Y1, ‘window‘, 340, 400, ‘red‘, ‘false‘)

  85: endwhile

  86: * Apply the measure tool and transform the resulting point coordinates

  87: * into the WCS

  88: dev_set_color (‘red‘)

  89: dev_display (Image)

  90: * Set the world coordinates of four points defining a ROI for the measure tool

  91: ROI_X_WCS := [-2,-2,112,112]

  92: ROI_Y_WCS := [0,0.5,0.5,0]

  93: ROI_Z_WCS := [0,0,0,0]

  94: * Determine the transformation matrix from the WCS into the CCS

  95: pose_to_hom_mat3d (FinalPose, CCS_HomMat_WCS)

  96: * Transform the point coordintes into the image coordinate system

  97: affine_trans_point_3d (CCS_HomMat_WCS, ROI_X_WCS, ROI_Y_WCS, ROI_Z_WCS, CCS_RectangleX, CCS_RectangleY, CCS_RectangleZ)

  98: project_3d_point (CCS_RectangleX, CCS_RectangleY, CCS_RectangleZ, CamParam, RectangleRow, RectangleCol)

  99: gen_region_polygon_filled (ROI, RectangleRow, RectangleCol)

 100: smallest_rectangle2 (ROI, RowCenterROI, ColCenterROI, PhiROI, Length1ROI, Length2ROI)

 101: * Create a measure

 102: gen_measure_rectangle2 (RowCenterROI, ColCenterROI, PhiROI, Length1ROI, Length2ROI, 652, 494, ‘bilinear‘, MeasureHandle)

 103: measure_pairs (Image, MeasureHandle, 0.4, 5, ‘all_strongest‘, ‘all‘, RowEdgeFirst, ColumnEdgeFirst, AmplitudeFirst, RowEdgeSecond, ColumnEdgeSecond, AmplitudeSecond, IntraDistance, InterDistance)

 104: close_measure (MeasureHandle)

 105: dev_display (Image)

 106: disp_message (WindowHandle, ‘Measuring the position of the pitch lines‘, ‘window‘, 450, 25, ‘red‘, ‘false‘)

 107: dev_set_color (‘green‘)

 108: RowPitchLine := (RowEdgeFirst+RowEdgeSecond)/2.0

 109: ColPitchLine := (ColumnEdgeFirst+ColumnEdgeSecond)/2.0

 110: disp_cross (WindowHandle, RowPitchLine, ColPitchLine, 6, 0)

 111: image_points_to_world_plane (CamParam, FinalPose, RowPitchLine, ColPitchLine, 1, X1, Y1)

 112: for i := 1 to |X1| by 1

 113:     set_tposition (WindowHandle, RowEdgeFirst[i-1]+5, ColumnEdgeFirst[i-1]-20)

 114:     if (i=|X1|)

 115:         set_tposition (WindowHandle, RowEdgeFirst[i-1], ColumnEdgeFirst[i-2])

 116:     endif

 117:     write_string (WindowHandle, X1[i-1]$‘.3f‘+‘mm‘)

 118: endfor

 119: disp_continue_message (WindowHandle, ‘black‘, ‘true‘)

 120: stop ()

 121: dev_display (Image)

 122: * Apply a line extraction and transform the resulting xld contours

 123: * into the WCS

 124: * Set the world coordinates of four points defining a ROI

 125: ROI_X_WCS := [11,11,13,13]

 126: ROI_Y_WCS := [4,6,6,4]

 127: ROI_Z_WCS := [0,0,0,0]

 128: * Transform the point coordinates into the image coordinate system

 129: affine_trans_point_3d (CCS_HomMat_WCS, ROI_X_WCS, ROI_Y_WCS, ROI_Z_WCS, CCS_RectangleX, CCS_RectangleY, CCS_RectangleZ)

 130: project_3d_point (CCS_RectangleX, CCS_RectangleY, CCS_RectangleZ, CamParam, RectangleRow, RectangleCol)

 131: * Visualize the square in the original image

 132: disp_polygon (WindowHandle, [RectangleRow,RectangleRow[0]], [RectangleCol,RectangleCol[0]])

 133: dev_display (Image)

 134: * create the ROI

 135: gen_region_polygon_filled (ROI, RectangleRow, RectangleCol)

 136: reduce_domain (Image, ROI, ImageReduced)

 137: * Extract the lines

 138: lines_gauss (ImageReduced, Lines, 1, 3, 8, ‘dark‘, ‘true‘, ‘bar-shaped‘, ‘true‘)

 139: * Adapt the pose of the measurement plane to the tilted plane of the vernier

 140: RelPose := [0,3.2,0,-14,0,0,0]

 141: pose_to_hom_mat3d (FinalPose, HomMat3D)

 142: pose_to_hom_mat3d (RelPose, HomMat3DRel)

 143: hom_mat3d_compose (HomMat3D, HomMat3DRel, HomMat3DAdapted)

 144: * Alternatively, the adaption can be done using the operators

 145: * hom_mat3d_translate_local and hom_mat3d_rotate_local

 146: * as shown in the following to lines

 147: hom_mat3d_translate_local (HomMat3D, 0, 3.2, 0, HomMat3DTranslate)

 148: hom_mat3d_rotate_local (HomMat3DTranslate, rad(-14), ‘x‘, HomMat3DAdapted)

 149: hom_mat3d_to_pose (HomMat3DAdapted, PoseAdapted)

 150: * Transform the xld contour to the WCS using the adapted pose

 151: contour_to_world_plane_xld (Lines, ContoursTrans, CamParam, PoseAdapted, 1)

 152: get_contour_xld (ContoursTrans, YOfContour, XOfContour)

 153: tuple_mean (XOfContour, MeterReading)

 154: dev_display (Lines)

 155: disp_message (WindowHandle, ‘Meter reading: ‘+MeterReading$‘.3f‘+‘mm‘, ‘window‘, 400, 180, ‘green‘, ‘false‘)

 156: disp_continue_message (WindowHandle, ‘black‘, ‘true‘)

 157: stop ()

 158: dev_close_inspect_ctrl (YOfContour)

 159: dev_close_inspect_ctrl (XOfContour)

 160: * Now, transform the whole image

 161: WidthMappedImage := 652

 162: HeightMappedImage := 494

 163: dev_display (Image)

 164: * First, determine the scale for the mapping

 165: * (here, the scale is determined such that in the

 166: *   surroundings of the points P0 and P1,  the image scale of the

 167: *   mapped image is similar to the image scale of the original image)

 168: distance_pp (X[0], Y[0], X[1], Y[1], DistP0P1WCS)

 169: distance_pp (RCoord[0], CCoord[0], RCoord[1], CCoord[1], DistP0P1PCS)

 170: Scale := DistP0P1WCS/DistP0P1PCS

 171: * Then, determine the parameter settings for set_origin_pose such

 172: * that the point given via get_mbutton will be in the center of the

 173: * mapped image

 174: dev_display (Image)

 175: disp_message (WindowHandle, ‘Define the center of the mapped image‘, ‘window‘, 12, 12, ‘red‘, ‘false‘)

 176: get_mbutton (WindowHandle, CenterRow, CenterColumn, Button1)

 177: image_points_to_world_plane (CamParam, FinalPose, CenterRow, CenterColumn, 1, CenterX, CenterY)

 178: set_origin_pose (FinalPose, CenterX-Scale*WidthMappedImage/2.0, CenterY-Scale*HeightMappedImage/2.0, 0, PoseNewOrigin)

 179: gen_image_to_world_plane_map (Map, CamParam, PoseNewOrigin, 652, 494, WidthMappedImage, HeightMappedImage, Scale, ‘bilinear‘)

 180: map_image (Image, Map, ImageMapped)

 181: dev_clear_window ()

 182: dev_display (ImageMapped)

 183: * In case, only one image has to be mapped, the operator

 184: * image_to_world_plane can be used instead of the operators

 185: * gen_image_to_world_plane_map together with map_image.

 186: image_to_world_plane (Image, ImageMapped, CamParam, PoseNewOrigin, WidthMappedImage, HeightMappedImage, Scale, ‘bilinear‘)