It's normal for the DFS pointcloud to be very sparse with our default settings. As you can see in the filtered images, there's very little usable data in environments with flat white walls. We find that the filters help remove a lot of the noise that you can see in the raw disparity image, but it doesn't usually look quite so sparse. My two recommendations for you would be to
A) Refocus and recalibrate your stereo cameras. It looks like your right stereo image is slightly out of focus, which won't help, and any small changes to the orientation of the cameras with regards to each other will lead to significant issues with dfs, they'll need a strong calibration. The lenses themselves tend not to change over time at all, so you can likely skip the intrinsics portion of the stereo cal process and skip straight to the extrinsics.
B) Play with the filter settings in
/etc/modalai/voxl-dfs-server.conf to your liking. By default, we apply a 17-pixel median filter and then a second 7-pixel median filter, which is a pretty heavy filter process and is intended to produce low-res/low-noise/obstacle avoidance friendly images, not high-res disparity images. You can remove the second filter entirely and/or lower either of the values to have something closer to the original image based on your use case.