Depth image shows wrong information (Proximity Distortion)

The goal of my current project is to determine the location of an “object” with just its 3D-coordinates. To achieve that I figured it’d be best to turn off the “Fill”-Mode of my Camera (Zed 2).

The Problem:

The depth image is being distorted to a major degree due to proximity of other “objects”.

The following image shows the depth image from the side, it is viewing some bars before a smooth woodwall. The wall is mostly plain, so everything is fine here. I blacked the Color-Image and Myself, do not worry about those parts.

When I put my hand or another object in front of the wood wall parts that are bigger than my actual hand get “pulled” towards the camera around the location of the hand or other object. These parts seem to “stick” to other elevated parts in the proximity, as the area between the bars and my arm gets pulled entirely.

Question(s):

  1. Is this normal?
  2. Is there an easy way to get rid of it?
  3. What is the reason behind it?

My own assumption(s):

  1. Feel like this is some sort of approximation of unknown parts
  2. Hopefully… Glad the camera was calibrated by default, as that usually is a pain to do right.
  3. Due to the new object that gets put in front of the wall, there is more stuff hidden and therefore more areas that the camera cannot see with both lenses, maybe it just “guesses” that the area between is not so far off due to some underlying algorithms that make the image smoother…

Additional Info:
Today I retried the same but put a blanket over the wall to give it more texture, which unfortunately did not help in every regard, but the distortion was a little less. The problem is though, that from the bar in the image (6cm x 50cm) the upper ~15cm get pulled towards the background wall… Which is rather much in my opinion. With larger ones (~6cm x 100cm or longer) sometimes the middle parts get pulled entirely, so that a recognition is almost impossible.

Any feedback on Kremerf entry? Interested by Stereolabs view on this.

The first level support suggested to change some threshold values (RuntimeParameters Class Reference | API Reference | Stereolabs). That wouldn’t fix the actual error in the software in my opinion, but could be of help. Unfortunately I can not test that, as due to the pandemic I can’t visit the lab…