I’m can see in Telemetry section that pose information of Stereo Camera is available but not for Front Camera (Telemetry list - 7.7). Is there a way to get attitude and position of front camera, in global frame like fstcam@pose ? I see there is fcam@eis@video that has attitude but in NED_start.
Also, I can see intrinsic parameters of front camera in fcam@settings@photo (Telemetry list - 7.7) like focal, principal_point_x, perspective.r* and perspective.t*, but this is available only when picture is taken. Is there a way to get these info when using video ? Or should we take a picture each time we want to get these infos ?
Regarding the attitude of the front camera in NED frame, you have 2 solutions :
Use fcam@eis@video.view_ned_start_q (I suggest you use this one instead of attitude_ned_start_q, as the former takes into account the effect of digital image stabilization) which will give you the attitude of video frames in NED_start. Then get drone_controller.ned_ned_start_q, which will give you the NED frame expressed in NED_start frame, then compute quaternion_conjugate(drone_controller.ned_ned_start_q) * fcam@eis@video.view_ned_start_q (where “*” is quaternion multiplication) to get the attitude of video frames in NED frame.
Extract the video metadata following Embedded Video Metadata - GroundSDK Tools 7.0 and get CameraMetadata.quat, which will directly give you the attitude of video frames in NED frame.
Regarding the position of the front camera : as for now, the position of the front camera in the global frame is not exported.
Regarding camera intrinsic parameters in video mode, you can use the following formulas to compute them:
focal_in_px = video_width / (2 * tan(fcam@eis@video.hfov / 2))
principal_point_x = video_width / 2
principal_point_y = video_height / 2
no radial / tangential distortion (as distortion is corrected by the drone in all video modes).
Unfortunately, fcam@eis@photo only publish each time a photo is taken, so I guess nothing when using fcam_streaming. But I’ll do it with fcam@eis@video.
For intrinsic parameters, I’m impressed distortion is corrected onboard in realtime in all video modes. Are you sure about that ?
Yes, sorry I fixed my message, I meant fcam@eis@video. Yes the distortion is corrected onboard for video modes, otherwise the images would look like the photo JPEG wide mode (in which no distortion correction is performed).