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stereoCalibrationErrors

Object for storing standard errors of estimated stereo parameters

Description

The stereoCalibrationErrors object contains the standard errors of estimated stereo parameters. You can access the standard errors for stereo calibration using the object properties. You can display the standard errors using the displayErrors object function.

Creation

Syntax

[params,imgsUsed,Errors] = estimateCameraParameters(imagePoints,worldPoints)

Description

[params,imgsUsed,Errors] = estimateCameraParameters(imagePoints,worldPoints) creates a stereoCalibrationErrors object by calling the estimateCameraParameters function with image points and world points from a stereo camera. The function returns the stereoCalibrationErrors object as the third output argument. .

Properties

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Standard errors of for camera one estimated intrinsics and distortion coefficients, specified as an intrinsicsEstimationErrors object.

Standard errors of camera one estimated extrinsics, specified as an extrinsicsEstimationErrors object.

Standard errors of for camera two estimated intrinsics and distortion coefficients, specified as an intrinsicsEstimationErrors object.

Standard errors of the rotated vector of camera two relative to camera one, specified as a three-element vector.

Standard errors of the translation of camera two relative to camera one, specified as a three-element vector.

Object Functions

displayErrorsDisplay standard errors of camera parameter estimates

Examples

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Specify two sets of calibration images.

imageDir = fullfile(toolboxdir("vision"),"visiondata", ...
  "calibration","stereo");
leftImages = imageDatastore(fullfile(imageDir,"left"));
rightImages = imageDatastore(fullfile(imageDir,"right"));

Detect the checkerboards.

[imagePoints,boardSize] = detectCheckerboardPoints( ...
  leftImages.Files,rightImages.Files);

Generate the world coordinates of the corners of the squares. Square size is in millimeters.

squareSize = 108;
worldPoints = generateCheckerboardPoints(boardSize,squareSize);

Calibrate the stereo camera system. Here, both cameras have the same resolution.

I = readimage(leftImages,1); 
imageSize = [size(I,1) size(I,2)];
[params, ~, errors] = estimateCameraParameters(imagePoints,worldPoints, ...
                                  ImageSize=imageSize);

Display standard stereo calibration errors.

displayErrors(errors,params);
			Standard Errors of Estimated Stereo Camera Parameters
			-----------------------------------------------------

Camera 1 Intrinsics
-------------------
Focal length (pixels):   [ 1038.0286 +/- 0.6533     1037.9144 +/- 0.6389  ]
Principal point (pixels):[  656.0841 +/- 0.3408      485.5485 +/- 0.2639  ]
Radial distortion:       [   -0.3617 +/- 0.0008        0.1866 +/- 0.0026  ]

Camera 1 Extrinsics
-------------------
Rotation vectors:
                         [    0.1680 +/- 0.0007       -0.0271 +/- 0.0006        3.1125 +/- 0.0001  ]
                         [    0.1995 +/- 0.0006       -0.0523 +/- 0.0005       -3.0991 +/- 0.0000  ]
                         [    0.4187 +/- 0.0005       -0.1061 +/- 0.0004       -3.1113 +/- 0.0001  ]
                         [    0.5239 +/- 0.0005       -0.0604 +/- 0.0004       -3.0552 +/- 0.0001  ]
                         [    0.6807 +/- 0.0006       -0.0306 +/- 0.0005       -3.0331 +/- 0.0001  ]
                         [    0.3513 +/- 0.0007       -0.0993 +/- 0.0006       -3.0334 +/- 0.0001  ]
                         [    0.0212 +/- 0.0007       -0.1179 +/- 0.0007       -3.0833 +/- 0.0000  ]
                         [   -0.2765 +/- 0.0008       -0.0847 +/- 0.0007       -3.0943 +/- 0.0001  ]
                         [   -0.4407 +/- 0.0007       -0.1119 +/- 0.0006       -3.0652 +/- 0.0001  ]
                         [   -0.2537 +/- 0.0008       -0.1334 +/- 0.0007       -3.1039 +/- 0.0001  ]

Translation vectors (mm):
                         [  708.4192 +/- 0.4914      227.0500 +/- 0.4002     1492.8672 +/- 1.0127  ]
                         [  368.4409 +/- 0.5228      191.7200 +/- 0.4094     1589.9146 +/- 0.9987  ]
                         [  226.3710 +/- 0.5173      191.1430 +/- 0.4030     1578.4779 +/- 0.9576  ]
                         [   49.5377 +/- 0.5183      196.7495 +/- 0.4030     1580.5403 +/- 0.9493  ]
                         [ -172.4001 +/- 0.7003      150.9910 +/- 0.5406     2119.3253 +/- 1.2532  ]
                         [   10.7777 +/- 0.6784      176.8785 +/- 0.5276     2066.8343 +/- 1.2907  ]
                         [  295.4840 +/- 0.6616      167.8675 +/- 0.5158     2010.7712 +/- 1.2738  ]
                         [  614.2338 +/- 0.6457      166.2016 +/- 0.5153     1968.1798 +/- 1.2722  ]
                         [  767.0157 +/- 0.6106      165.5372 +/- 0.4991     1868.3334 +/- 1.2395  ]
                         [  953.8134 +/- 0.7336      -14.7981 +/- 0.6039     2255.6169 +/- 1.5107  ]

Camera 2 Intrinsics
-------------------
Focal length (pixels):   [ 1042.4816 +/- 0.6644     1042.2691 +/- 0.6534  ]
Principal point (pixels):[  640.5972 +/- 0.3305      479.0652 +/- 0.2633  ]
Radial distortion:       [   -0.3614 +/- 0.0007        0.1822 +/- 0.0022  ]

Position And Orientation of Camera 2 Relative to Camera 1
---------------------------------------------------------
Rotation of camera 2:         [   -0.0037 +/- 0.0002        0.0050 +/- 0.0004       -0.0002 +/- 0.0000  ]
Translation of camera 2 (mm): [ -119.8720 +/- 0.0401       -0.4005 +/- 0.0414       -0.0258 +/- 0.1750  ]
Introduced in R2014b