Camera calibration parameters format

[clement-joly]

Hi, I can't figure out how to update the reprojection parameters in the camera yaml file.

Here is what I'm doing: I'm trying to run the OKVIS sample. Before running it I'm trying to update the camera calibration parameters in config/config_mynteye.yaml as suggested in the OKVIS SLAM documentation. After running "./samples/_output/bin/tutorials/get_img_params" and getting the output I can't figure out where to get the reprojection parameters from (distortion parameters, focal length and principal point are easy to figure out).

Here is what ./get_img_params outputs:

I/get_img_params.cc:44 Intrinsics left: {equidistant, width: 752, height: 480, k2: -0.02792783570059486, k3: 0.01786521154646784, k4: -0.02664344274294007, k5: 0.01070160112850720, mu: 367.99913111190255677, mv: 367.81784687988840687, u0: 374.05615779570649693, v0: 240.30372535340484319}
I/get_img_params.cc:45 Intrinsics right: {equidistant, width: 752, height: 480, k2: -0.02414661189360028, k3: 0.00185208096833369, k4: -0.00304351025845435, k5: -0.00024005929378344, mu: 366.68144499080142396, mv: 366.76898727690240776, u0: 388.11237425751852470, v0: 236.91823718560618772}
I/get_img_params.cc:46 Extrinsics right to left: {rotation: [0.99995681220526167, 0.00152430418018631, -0.00916789076381803, -0.00157537598817912, 0.99998326829449113, -0.00556608673698824, 0.00915925296008916, 0.00558028922494831, 0.99994248257456242], translation: [-120.42460893053265636, -0.02764270343508017, -0.49606529118166043]}
ROSMsgInfoPair:
left:
width: 640, height: 400
distortion_model: PINHOLE
D: -0.250348,0.0505794,-0.000705367,-0.00852555,0,
K: 362.201,0,363.501,0,406.587,234.352,0,0,1,
R: 0.995541,0.00317344,0.0942805,-0.00350544,0.999988,0.00335595,-0.0942688,-0.00367148,0.99554,
P: 349.09,0,374.036,0,0,349.09,251.158,0,0,0,1,0,

right:
width: 640, height: 400
distortion_model: PINHOLE
D: -0.250348,0.0505794,-0.000705367,-0.00852555,0,
K: 362.201,0,363.501,0,406.587,234.352,0,0,1,
R: 0.999013,0.00980714,0.04333,-0.00967418,0.999948,-0.00327717,-0.0433599,0.00285476,0.999055,
P: 349.09,0,374.036,-41940.9,0,349.09,251.158,0,0,0,1,0,

And here is the format of the yaml file that I need to update:

cameras:
    - {T_SC:
       [-0.00702012, -0.99996421, -0.00472216, 0.00397678,
        0.99997478, -0.00702512, 0.0010427, -0.04320474,
        -0.00107584, -0.00471472, 0.99998831, 0.02690585,
          0.0, 0.0, 0.0, 1.0],
       image_dimension: [752, 480],
       distortion_coefficients: [-3.0528777663428153e-01, 8.1448686969566128e-02, 4.2202500511119567e-04, 4.3984930436069997e-04],
       distortion_type: radialtangential,
       focal_length: [3.5930674755329585e+02, 3.6049533700817784e+02],
       principal_point: [3.8914180654924951e+02, 2.5282994170020979e+02]}

    - {T_SC:
       [ 0.00190458, -0.99999508, -0.0024922, 0.00337758,
        0.99999677, 0.00190877, -0.00167832, 0.07660769,
        0.00168307, -0.002489, 0.99999549, 0.02699279,
          0.0, 0.0, 0.0, 1.0],
       image_dimension: [752, 480],
       distortion_coefficients: [-3.0291415447136244e-01, 8.1192486081665002e-02, -3.0849058731388272e-04, 2.3295083728201271e-04],
       distortion_type: radialtangential,
       focal_length: [3.5693477648078687e+02, 3.5803785465032320e+02],
       principal_point: [3.7966613895215522e+02, 2.5597274516015744e+02]}

How do I update the two 4x4 matrices above (after T_SC)?

I've also tried to generate the yaml file directly by running ./tools/_output/bin/writer/img_params_writer tools/writer/config/img.params but I get a segmentation error ... any idea why?

I/utils.cc:35 Detecting MYNT EYE devices
Segmentation fault

I'm running this on an ARM platform (Odroid XU4, Ubuntu 16.04.4 LTS) Thanks!

[alter-sachin]

Were you able to find a way ?