Orientation of spherical cameras

[uop360]

Can you please explain how yaw, pitch, roll is defined for spherical cameras mounted on a top of a car?
How the axis of the image  is defined in relation to equirectangular format?
KK

[HMArnold]

Although I have never worked with spherical camera arrays,  I would think each image would have a pitch value of the number of degrees from vertical the camera is mounted, a yaw value equal to the angle the camera is pointed from the front of the car, corrected for the direction the car is pointed when each image is taken, and a roll value of zero assuming the car is traveling flat.

If a camera is mounted pointed to the right side of the vehicle and down 30 degrees from the horizon, and an image was taken when the car was on a compass heading of 225 when an image was taken, the yaw value would be -45  (225+90 = 345 compass which is 45 degrees left of North), the pitch would be 60 (90-30), and the roll would be zero

[Alexey Pasumansky]

Hello uop360,

Assuming that IMU measured angles  are yaw = 0, pitch = 0, roll = 0 while the car is moving to the north on the plain road and center of the spherical image is pointing to the car's movement direction, the correction angle for the pitch in the Offset tab of Camera Calibration window should be "-90" degrees, as offset is estimated in the camera coordinate system.

So actually it is the same, as for common frame camera, you just need to pay attention to the central point of the spherical panorama, as it defines the orientation of the camera.