There are singularities in the optical flow generated by NVIDIA Optical Flow SDK

Hi all,

I am totally a freshman as NVIDIA API user.

I am confused to discover that there are some singularities in the optical flow generated by NVIDIA Optical Flow SDK, like at the top of attachment “grove3_nvidia_flows.png”.
For comparison, groud truth is uploaded as “grove3_ground_truth.png”.

I just compiled the Optical_Flow_SDK_1.0.13 and run the command on 2080Ti:

./AppOFCuda/AppOFCuda --input="mypath/Grove3/*.png"

Did I do something wrong?

Many thanks in advance for your consideration.
grove3_ground_truth.png
grove3_nvidia_flows.png