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

Gaming and Visualization Technologies Video Processing & Optical Flow
1

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_ground_truth.png880×320 57.1 KB

grove3_nvidia_flows.png
grove3_nvidia_flows.png880×320 18.2 KB

2

I noticed the same thing. I ran tests a couple months ago with sample images that I translated by various amounts (both integer and fractional translations using texture lookups with linear filtering) up to 128 in X and Y. The errors correlate to the “speed” (“slow” has fewer and smaller than “medium”, which in turn has fewer and smaller than “fast”). Larger displacements generate more and larger errors and errors along the left edge as well.

Any insights from the nvidia devs would be welcome.

3

And I see the same issues with the 3.0 SDK on both the RTX 2080 and 3060.