what distance do depthmap values represent

RolfK

This question should be easy to answer.

Are the distances as output by the stereodepth node in the depth [mm] channel the line-of-sight distance between the camera sensor and the corresponding point in the depth map or are the distances calculated as the distance between the camera plane and the parallel plane on which the point in the depth map exists ?

A real world example is if the camera facing ( is perpendicular to ) a wall. Are all points on the wall at the same distance in the distance map (as they are in the same plane, parallel to the camera plane ) or do they have different distances ( as they have a different line of sight distance to the camera sensor ? ). Of course I can test this myself, but given noise, measurement confidence, and measurement errors I am still not sure about the findings ..

jakaskerl

RolfK re all points on the wall at the same distance in the distance map (as they are in the same plane, parallel to the camera plane ) or do they have different distances ( as they have a different line of sight distance to the camera sensor ? )

Yes. There might be slight variability due to radial distortion of the lens, but this should be relatively minimal since the images are undistorted.

Thanks,
Jaka

RolfK

I think you are telling me that depthmap values are the perpendicular distances between points and the camera plane, and not the line of sight distances. Thanks !