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  4. Camera calibration error on voxl 2

Camera calibration error on voxl 2

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  • Tamas Pal 0T Offline
    Tamas Pal 0T Offline
    Tamas Pal 0
    Regular
    wrote on last edited by Tamas Pal 0
    #1

    While calibrating the cameras I getting this error. How to fix it ?

    voxl2:/data/modalai$ voxl-calibrate-camera hires -s 6x9 -l 0.038
    Please open voxl-portal in a web browser to view the camera calibrator overlay stream
    Matrix
    [693.6691539302459, 0, 288.005823202943;
     0, 696.732504080016, 320.7673427167344;
     0, 0, 1]
    Distortion
    [0.1797394659934352;
     -0.2310619433685658;
     -0.003705138274410424;
     -0.006883924563489691;
     0]
    distortion_model: plumb_bob
    Re-projection error reported by calibrateCamera: 1.47713
    Calibration Failed
    Max reprojection error:  0.5
    Exiting Cleanly
    munmap_chunk(): invalid pointer
    Aborted
    

    vxlcalib4.png

    and

    voxl2:/data/modalai$ voxl-calibrate-camera hires --fisheye -s 6x9 -l 0.034
    Please open voxl-portal in a web browser to view the camera calibrator overlay stream
    Matrix
    [-367.8815041601071, -0, 330.2372757833328;
     0, -368.0547039271603, 319.7644104459951;
     0, 0, 1]
    Distortion
    [0.383366879780598;
     0.1689986582189106;
     0;
     0]
    distortion_model: fisheye
    Re-projection error reported by calibrateCamera: 1.54825
    Calibration Succeded!
    
    Writing data to: /data/modalai/opencv_hires_intrinsics.yml
    Saved!
    Exiting Cleanly
    
    Segmentation fault:
    Fault thread: voxl-calibrate-(tid: 14253)
    Fault address: 0x7f88000000
    Address not mapped.
    Segmentation fault
    
    1 Reply Last reply
    0
    • ? Offline
      ? Offline
      A Former User
      wrote on last edited by
      #2

      Hi,

      A couple things:

      1. You were on track in the first attempt, the hires camera shouldn't use the fisheye flag
      2. The main error here is the reprojection error indicating the calibration wasn't good enough for our standards. The culprit here looks like the camera is very out of focus. If you look at the hires camera on the board you'll be able to twist the lens to change the focal length, we recommend putting the checkerboard about as far away as you'd like to be using the hires camera to inspect things and then twist the lens until the checkerboard is crisp.
      3. The munmap/free issues: these seem to be an issue on our end when handling incoming color images. I think this is the first time that someone's attempted to calibrate the hires camera, and it's good that you brought this to our attention. I just pushed up a new version (0.2.3) of the calibrator tool to our staging branch that fixes this issue. You can install this version on your device by either:
        a) Switch your device to our staging branch following the docs here and installing the new version with apt. This is the easier of the two ways but will also put you on our pre-release branch, so be wary of any other updates that you do (though this is not our beta testing branch and things here are usually pretty stable)
        b) Manually download the package from this link and install it alone with dpkg. This is (only slightly) more involved but will also keep the rest of your projects on our most recent stable release.
      Tamas Pal 0T 3 Replies Last reply
      0
      • ? A Former User

        Hi,

        A couple things:

        1. You were on track in the first attempt, the hires camera shouldn't use the fisheye flag
        2. The main error here is the reprojection error indicating the calibration wasn't good enough for our standards. The culprit here looks like the camera is very out of focus. If you look at the hires camera on the board you'll be able to twist the lens to change the focal length, we recommend putting the checkerboard about as far away as you'd like to be using the hires camera to inspect things and then twist the lens until the checkerboard is crisp.
        3. The munmap/free issues: these seem to be an issue on our end when handling incoming color images. I think this is the first time that someone's attempted to calibrate the hires camera, and it's good that you brought this to our attention. I just pushed up a new version (0.2.3) of the calibrator tool to our staging branch that fixes this issue. You can install this version on your device by either:
          a) Switch your device to our staging branch following the docs here and installing the new version with apt. This is the easier of the two ways but will also put you on our pre-release branch, so be wary of any other updates that you do (though this is not our beta testing branch and things here are usually pretty stable)
          b) Manually download the package from this link and install it alone with dpkg. This is (only slightly) more involved but will also keep the rest of your projects on our most recent stable release.
        Tamas Pal 0T Offline
        Tamas Pal 0T Offline
        Tamas Pal 0
        Regular
        wrote on last edited by Tamas Pal 0
        #3

        @Alex-Gardner Thank you for you suggestions. I have upgraded the voxl-calibrate-camera and switched to staging version. The hires and tracking camera calibration is working fine now. But I am having some problem regading streo camera calibration. How to fix it ?

        voxl2:/$ voxl-calibrate-camera stereo_front -s 6x9 -l 0.034
        Please open voxl-portal in a web browser to view the camera calibrator overlay stream
        Calibrating Left Camera
        Matrix
        [500.4213862090265, 0, 346.3373792923238;
         0, 501.227740248529, 228.878072211419;
         0, 0, 1]
        Distortion
        [-0.1660913438796711;
         0.05755259725598761;
         0.000863652065816025;
         0.0005852774309940085;
         0]
        distortion_model: plumb_bob
        Re-projection error reported by calibrateCamera: 0.419252
        Calibration Succeded!
        Calibrating Right Camera
        Matrix
        [513.8225740415423, 0, 334.0143369611135;
         0, 514.1101484689675, 257.1884653194029;
         0, 0, 1]
        Distortion
        [-0.1736357276577499;
         0.07324720821732762;
         0.002579625065851226;
         -0.0002603134282297033;
         0]
        distortion_model: plumb_bob
        Re-projection error reported by calibrateCamera: 0.410086
        Calibration Succeded!
        Calibrating Extrinsics
        4 frames will be processed
        R
        [0.9990467365388441, -0.02586416972382951, 0.0351662186705121;
         0.02662023260498675, 0.9994207058449519, -0.02120414922685195;
         -0.03459741937112843, 0.02212006900701594, 0.9991565048179305]
        T
        [-0.07974387312689943;
         -0.001107340907051975;
         0.004462065261819127]
        Re-projection error reported by stereoCalibrate: 0.594130
        Detected horizontal stereo pair
        Distance between cameras: 0.0797
        Extrinsics Calibration Failed
        exceeded allowable max reprojection error:  0.5
        
        Saved intrinsics to: /data/modalai/opencv_stereo_front_intrinsics.yml
        Exiting Cleanly
        

        vxlcalib5.png

        Also for every case the re-projection error is more than 0.4. Is there anyway to make it below 0.2?

        1 Reply Last reply
        0
        • ? A Former User

          Hi,

          A couple things:

          1. You were on track in the first attempt, the hires camera shouldn't use the fisheye flag
          2. The main error here is the reprojection error indicating the calibration wasn't good enough for our standards. The culprit here looks like the camera is very out of focus. If you look at the hires camera on the board you'll be able to twist the lens to change the focal length, we recommend putting the checkerboard about as far away as you'd like to be using the hires camera to inspect things and then twist the lens until the checkerboard is crisp.
          3. The munmap/free issues: these seem to be an issue on our end when handling incoming color images. I think this is the first time that someone's attempted to calibrate the hires camera, and it's good that you brought this to our attention. I just pushed up a new version (0.2.3) of the calibrator tool to our staging branch that fixes this issue. You can install this version on your device by either:
            a) Switch your device to our staging branch following the docs here and installing the new version with apt. This is the easier of the two ways but will also put you on our pre-release branch, so be wary of any other updates that you do (though this is not our beta testing branch and things here are usually pretty stable)
            b) Manually download the package from this link and install it alone with dpkg. This is (only slightly) more involved but will also keep the rest of your projects on our most recent stable release.
          Tamas Pal 0T Offline
          Tamas Pal 0T Offline
          Tamas Pal 0
          Regular
          wrote on last edited by
          #4

          @Alex-Gardner After installing the packages from staging version the cameras are not working. How to solve it ?

          1 Reply Last reply
          0
          • ? A Former User

            Hi,

            A couple things:

            1. You were on track in the first attempt, the hires camera shouldn't use the fisheye flag
            2. The main error here is the reprojection error indicating the calibration wasn't good enough for our standards. The culprit here looks like the camera is very out of focus. If you look at the hires camera on the board you'll be able to twist the lens to change the focal length, we recommend putting the checkerboard about as far away as you'd like to be using the hires camera to inspect things and then twist the lens until the checkerboard is crisp.
            3. The munmap/free issues: these seem to be an issue on our end when handling incoming color images. I think this is the first time that someone's attempted to calibrate the hires camera, and it's good that you brought this to our attention. I just pushed up a new version (0.2.3) of the calibrator tool to our staging branch that fixes this issue. You can install this version on your device by either:
              a) Switch your device to our staging branch following the docs here and installing the new version with apt. This is the easier of the two ways but will also put you on our pre-release branch, so be wary of any other updates that you do (though this is not our beta testing branch and things here are usually pretty stable)
              b) Manually download the package from this link and install it alone with dpkg. This is (only slightly) more involved but will also keep the rest of your projects on our most recent stable release.
            Tamas Pal 0T Offline
            Tamas Pal 0T Offline
            Tamas Pal 0
            Regular
            wrote on last edited by Tamas Pal 0
            #5
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