Camera Calibration Parameters: .json relation to ROS .yaml?

farbod_f

Hello all!

Short version:

I have the result of calibration of an Oak-D PRO W as .json file. How do I use this to update my ROS2 .yaml camera parameters?
Long version:
Here is my .json file:
{

"batchName": "",
"batchTime": 1711976057,
"boardConf": "IR-C21M08-00",
"boardCustom": "",
"boardName": "DM9098",
"boardOptions": 1048580,
"boardRev": "R8M2E8",
"cameraData": [
[
1,
{
"cameraType": 0,
"distortionCoeff": [
4.717190742492676,
1.3956365585327148,
-6.380402919603512e-05,
0.0001253595546586439,
0.023136362433433533,
5.081787586212158,
2.8329949378967285,
0.19467654824256897,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0
],
"extrinsics": {
"rotationMatrix": [
[
0.999902606010437,
0.012355554848909378,
-0.006492577493190765
],
[
-0.012324679642915726,
0.999912679195404,
0.004774123430252075
],
[
0.006550997495651245,
-0.00469363946467638,
0.9999675154685974
]
],
"specTranslation": {
"x": -7.483457565307617,
"y": 0.0403454452753067,
"z": -0.03899169713258743
},
"toCameraSocket": 2,
"translation": {
"x": -7.483457565307617,
"y": 0.0403454452753067,
"z": -0.03899169713258743
}
},
"height": 800,
"intrinsicMatrix": [
[
575.97900390625,
0.0,
617.248046875
],
[
0.0,
575.8177490234375,
399.3473205566406
],
[
0.0,
0.0,
1.0
]
],
"lensPosition": 0,
"specHfovDeg": 127.0,
"width": 1280
}
],
[
0,
{
"cameraType": 0,
"distortionCoeff": [
6.249095916748047,
24.564743041992188,
-0.00013124215183779597,
0.00021829686011187732,
1.086168885231018,
6.282415866851807,
26.701169967651367,
5.43357515335083,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0
],
"extrinsics": {
"rotationMatrix": [
[
0.0,
0.0,
0.0
],
[
0.0,
0.0,
0.0
],
[
0.0,
0.0,
0.0
]
],
"specTranslation": {
"x": -0.0,
"y": -0.0,
"z": -0.0
},
"toCameraSocket": -1,
"translation": {
"x": 0.0,
"y": 0.0,
"z": 0.0
}
},
"height": 2160,
"intrinsicMatrix": [
[
2302.709228515625,
0.0,
1927.749755859375
],
[
0.0,
2302.032958984375,
1101.0440673828125
],
[
0.0,
0.0,
1.0
]
],
"lensPosition": 0,
"specHfovDeg": 108.0,
"width": 3840
}
],
[
2,
{
"cameraType": 0,
"distortionCoeff": [
0.329525351524353,
-0.025675591081380844,
3.1699910323368385e-05,
4.9789938202593476e-05,
-0.000945782579947263,
0.6532717347145081,
0.004792321473360062,
-0.006089592352509499,
0.0,
0.0,
0.0,
0.0,
0.0,
0.0
],
"extrinsics": {
"rotationMatrix": [
[
0.9999189376831055,
-0.012608837336301804,
0.0017703291960060596
],
[
0.012609267607331276,
0.9999204874038696,
-0.00023202858574222773
],
[
-0.0017672628164291382,
0.00025433232076466084,
0.9999983906745911
]
],
"specTranslation": {
"x": 3.75,
"y": 0.0,
"z": 0.0
},
"toCameraSocket": 0,
"translation": {
"x": 3.7869951725006104,
"y": 0.02553650178015232,
"z": -0.05815478041768074
}
},
"height": 800,
"intrinsicMatrix": [
[
559.5569458007813,
0.0,
653.0762939453125
],
[
0.0,
559.4925537109375,
366.91534423828125
],
[
0.0,
0.0,
1.0
]
],
"lensPosition": 0,
"specHfovDeg": 127.0,
"width": 1280
}
]
],
"deviceName": "",
"hardwareConf": "F1-FV01-BC000",
"housingExtrinsics": {
"rotationMatrix": [],
"specTranslation": {
"x": 0.0,
"y": 0.0,
"z": 0.0
},
"toCameraSocket": -1,
"translation": {
"x": 0.0,
"y": 0.0,
"z": 0.0
}
},
"imuExtrinsics": {
"rotationMatrix": [
[
0.0,
0.0,
0.0
],
[
0.0,
0.0,
0.0
],
[
0.0,
0.0,
0.0
]
],
"specTranslation": {
"x": 0.0,
"y": 0.0,
"z": 0.0
},
"toCameraSocket": -1,
"translation": {
"x": 0.0,
"y": 0.0,
"z": 0.0
}
},
"miscellaneousData": [],
"productName": "OAK-D-PRO-W",
"stereoEnableDistortionCorrection": true,
"stereoRectificationData": {
"leftCameraSocket": 1,
"rectifiedRotationLeft": [
[
0.9999750852584839,
0.006940091028809547,
-0.0013080642092972994
],
[
-0.0069361235946416855,
0.9999713897705078,
0.003013534704223275
],
[
0.0013289409689605236,
-0.0030043867882341146,
0.9999945759773254
]
],
"rectifiedRotationRight": [
[
0.9999639987945557,
-0.005229807924479246,
0.006683045998215675
],
[
0.005249893758445978,
0.9999817609786987,
-0.0029914637561887503
],
[
-0.006667279172688723,
0.00302644120529294,
0.9999731779098511
]
],
"rightCameraSocket": 2
},
"stereoUseSpecTranslation": false,
"version": 7,
"verticalCameraSocket": -1
}
Here is the ROS2 .yaml file for the color camera (the left and right cameras' files look the same!)

camera_matrix:
cols: 3
data: [ 1537.05322265625, 0.000000, 970.5643310546875, 0.000000, 1535.1085205078125, 509.2059020996094, 0.000000, 0.000000, 1.000000]
rows: 3
camera_name: color
distortion_coefficients:
cols: 14
data: [-1.872860, 16.683033, 0.001053, -0.002063, 61.878521, -2.158907, 18.424637,
57.682858, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000]
rows: 1
distortion_model: plumb_bob
image_height: 1080
image_width: 1920
projection_matrix:
cols: 3
data: [1479.458984, 0.000000, 950.694458, 0.0,
0.0, 1477.587158, 530.697632, 0.0,
0.0, 0.0, 1.0, 0.0]
rows: 4
rectification_matrix:
cols: 3
data: [0.9997062937394856, -0.023389961528659683, 0.006343181957754751, 0.0233922879452606,
0.999726320114537, -0.0002928052810344399, -0.006334597252184302, 0.0004411008211352551,
0.9999798389506251]
rows: 3

Any help is appreciated!

jakaskerl

farbod_f
cc @Luxonis-Adam

Luxonis-Adam

Hi @farbod_f, what is the exact use case? Is your camera not properly calibrated or did you need to do the recalibration? I think you should be able to recompute the distortion model according to this comment, but that involves some extra steps (or recalibration via ROS tools). If you just mean how to save the current calibration into the file, there should be a built-in service for saving calibration into a file provided by camera calibration manager used by each topic.

farbod_f

Luxonis-Adam

Hi there!

Short version:
I got the .json file directly from Luxonis, and want to convert it to 3 YAML files to use with the Luxonis ROS2 driver to generate/publish a point cloud in ROS2. How do I do that?

Long version:

I am using the ROS2 driver for the Oak-D camera to publish a point cloud.

The repository is here:
luxonis/depthai-rostree/humble/depthai_ros_driver

Specifically, there are three YAML files in the folder:

/depthai_examples/params/camera

for the left, right, and color cameras.

I did not calibrate the camera myself. There is a service by Luxonis found here:

https://preview.luxonis.com/stereo-tuning-assistance

that calibrates the camera for you. I got the .json file from Luxonis using that service.

Now, I want to convert that .json file to replace the 3 generic YAML files that come with the ROS2 driver on Github.

Questions:
1) How do I do that?
2) Do I need to do that? Or can I just flash the new calibration to the camera and forgo the YAML files?

Any help is appreciated.

Thanks so much!

Luxonis-Adam

Hi,

These three files are not by the driver, they are just to show an example of how ROS calibration files could look like after ROS(not DepthAI) calibration.
If you have the calibration.json file there are two options:
Either flash calibration manually as described in here https://docs.luxonis.com/software/depthai/examples/calibration_flash/
A bit simpler - you can pass calibration file to the driver so it loads it in runtime. To do that, set camera.i_external_calibration_path : path_to_file parameter in your yaml config file that you pass to the driver.

farbod_f

Luxonis-Adam

Hi!

That explains it. I went ahead and manually flashed the calibration.

Thanks so much!