Where to find the ToF and Hires sensors calibration?
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Hello, I have the Starling Max with the C29 cameras.
I am able to find intrinsic calibration files for the tracking cameras.
:~$ voxl-check-calibration Calibration File Status: Present /data/modalai/voxl-imu-server.cal Present /data/modalai/opencv_tracking_front_intrinsics.yml Present /data/modalai/opencv_tracking_down_intrinsics.yml Present /data/px4/param/parameters_gyro.cal Present /data/px4/param/parameters_acc.cal Present /data/px4/param/parameters_level.cal Present /data/px4/param/parameters_baro_tc.cal Present /data/px4/param/parameters_mag.calI am trying to get the ToF and Hires camera calibration.
Since ToF also publishes a point cloud, the intrinsics must be there already somewhere for ToF at least ?
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I am also interested for the ToF, and I have the C29 config as well. I tried using voxl-calibrate-camera on the tof_ir stream but it seems I will need a checkerboard with different reflectivity for the black and white squares (my printed one doesn't work well). However, I was able to generate an intrinsics calibration file just fine with my printed checkerboard for the hires camera.
My guess is the intrinsics for the ToF are hard-coded into the sensor itself and not handled by ModalAI directly, but I don't know for sure.
Any suggestions for the ToF sensor would be appreciated.
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I am also interested for the ToF, and I have the C29 config as well. I tried using voxl-calibrate-camera on the tof_ir stream but it seems I will need a checkerboard with different reflectivity for the black and white squares (my printed one doesn't work well). However, I was able to generate an intrinsics calibration file just fine with my printed checkerboard for the hires camera.
My guess is the intrinsics for the ToF are hard-coded into the sensor itself and not handled by ModalAI directly, but I don't know for sure.
Any suggestions for the ToF sensor would be appreciated.
@jimbow77 and @oasisartisan ,
TOF V1 (which is now EOL, so you don't have it on Starling 2 Max) was set up the following way:
- The calibration data was downloaded the first time the sensor was used and stored in
/data/misc/camera/, then re-used for next time - calibration files include
pmd.spc,tof_cal_eeprom.binandirs10x0c_lens.cal- the latter likely containing the intrinsics calibraiton data (although i have not checked explicitly)
TOF V2 (what is shipping in Starling 2 (and Max) ), is set up so that the TOF Library downloads (via i2c) the calibration data each time the
voxl-camera-serverstarts. This is done internally to the TOF libraries. I don't know exactly why there is a difference between how the calib data is handled for two sensors by the TOF software, but this is how our sensor vendor helped us set it up. The TOF processing software downloads the calibration from the sensor each time voxl-camera-server starts and applies it to generate the point cloud. It may be possible to get the TOF intrinsics using the TOF library API, but we have not checked.Do you have a specific reason why the TOF intrinsics are needed?
If you wanted to calibrate the TOF sensor yourself, then you would either need a checkerboard some material that is IR reflective ("white") and non-reflective ("black"). Alternatively, you could use an array of IR leds (or IR reflective dots + IR light) and use dot pattern detector as opposed for checkerboard for calibration.
Regarding Hi-res cameras, the intrinsics are not calibrated and not included. It can be calibrated using our camera calibration app (voxl-camera-calibration), but you should do it at half resolution or smaller (not full size like 4056x3040), otherwise the app runs very slowly. If you need more details how to calibrate at high resolution, let me know (involves downscaling exactly by a factor of 2 and then upscaling the resulting intrinsics)
Alex
- The calibration data was downloaded the first time the sensor was used and stored in
-
@jimbow77 and @oasisartisan ,
TOF V1 (which is now EOL, so you don't have it on Starling 2 Max) was set up the following way:
- The calibration data was downloaded the first time the sensor was used and stored in
/data/misc/camera/, then re-used for next time - calibration files include
pmd.spc,tof_cal_eeprom.binandirs10x0c_lens.cal- the latter likely containing the intrinsics calibraiton data (although i have not checked explicitly)
TOF V2 (what is shipping in Starling 2 (and Max) ), is set up so that the TOF Library downloads (via i2c) the calibration data each time the
voxl-camera-serverstarts. This is done internally to the TOF libraries. I don't know exactly why there is a difference between how the calib data is handled for two sensors by the TOF software, but this is how our sensor vendor helped us set it up. The TOF processing software downloads the calibration from the sensor each time voxl-camera-server starts and applies it to generate the point cloud. It may be possible to get the TOF intrinsics using the TOF library API, but we have not checked.Do you have a specific reason why the TOF intrinsics are needed?
If you wanted to calibrate the TOF sensor yourself, then you would either need a checkerboard some material that is IR reflective ("white") and non-reflective ("black"). Alternatively, you could use an array of IR leds (or IR reflective dots + IR light) and use dot pattern detector as opposed for checkerboard for calibration.
Regarding Hi-res cameras, the intrinsics are not calibrated and not included. It can be calibrated using our camera calibration app (voxl-camera-calibration), but you should do it at half resolution or smaller (not full size like 4056x3040), otherwise the app runs very slowly. If you need more details how to calibrate at high resolution, let me know (involves downscaling exactly by a factor of 2 and then upscaling the resulting intrinsics)
Alex
@Alex-Kushleyev Thank you.
Doing RGB calibration myself should be straightforward.
The reason I am interested in ToF intrinsics is I am interested in using the IR and the confidence images of the ToF as well. Which are not captured by the pointcloud.
Thanks for clarifying this is very useful.
- The calibration data was downloaded the first time the sensor was used and stored in
-
@Alex-Kushleyev Thank you.
Doing RGB calibration myself should be straightforward.
The reason I am interested in ToF intrinsics is I am interested in using the IR and the confidence images of the ToF as well. Which are not captured by the pointcloud.
Thanks for clarifying this is very useful.
@oasisartisan , I just checked the API for the TOF sensor and it seems we can get the lens calibration. I would need to make a change in the voxl camera server to try it. Please give me a few days..
Alex
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@oasisartisan , I just checked the API for the TOF sensor and it seems we can get the lens calibration. I would need to make a change in the voxl camera server to try it. Please give me a few days..
Alex
@Alex-Kushleyev I'm also interested for the same reasons as @oasisartisan. Thanks a lot for looking into this!
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@Alex-Kushleyev I'm also interested for the same reasons as @oasisartisan. Thanks a lot for looking into this!
Hi @jimbow77 , @oasisartisan ,
I updated the
voxl-camera-serveron a branch to save the tof v2 calibration to a file. Here is the commit : https://gitlab.com/voxl-public/voxl-sdk/services/voxl-camera-server/-/commit/f7aadc13246df35757498ee8c2633897864d47ff .Are you able to build the camera server from this branch?
https://gitlab.com/voxl-public/voxl-sdk/services/voxl-camera-server/-/tree/save-tof-v2-lens-calWe will review the changes more thoroughly a bit later and we can merge them to dev..
On my drone, the calibration file (which will include the serial number of the TOF sensor) is created when running camera server:
cat /data/misc/camera/irs2975c_8E7F-3715-16E7-2CA0_lens.cal VERSION:1.0:VERSION #px,py,cx,cy,tan-coeff[0..1], rad-coeff[0..n-1] 120.985 87.9267 101.435 101.435 0.000431714 -0.000511291 -0.0315991 -0.0224586 0.00496448Alex
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Hi @jimbow77 , @oasisartisan ,
I updated the
voxl-camera-serveron a branch to save the tof v2 calibration to a file. Here is the commit : https://gitlab.com/voxl-public/voxl-sdk/services/voxl-camera-server/-/commit/f7aadc13246df35757498ee8c2633897864d47ff .Are you able to build the camera server from this branch?
https://gitlab.com/voxl-public/voxl-sdk/services/voxl-camera-server/-/tree/save-tof-v2-lens-calWe will review the changes more thoroughly a bit later and we can merge them to dev..
On my drone, the calibration file (which will include the serial number of the TOF sensor) is created when running camera server:
cat /data/misc/camera/irs2975c_8E7F-3715-16E7-2CA0_lens.cal VERSION:1.0:VERSION #px,py,cx,cy,tan-coeff[0..1], rad-coeff[0..n-1] 120.985 87.9267 101.435 101.435 0.000431714 -0.000511291 -0.0315991 -0.0224586 0.00496448Alex
@Alex-Kushleyev Thank you so much!
I'm a bit preoccupied with a few other projects but hopefully I can take a look by the end of next week and get back to you.
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