Robust LineFit3D with STC-0038

When working in 3D – basic operations like line, plane and cylinder fitters are extremely important functions. Based on Scorpion Vision unique component technology we have upgraded the STC-0038-FitLine3D with the option to do a very robust 3D line fit.

stc-0038-fitline3d_setup — Configuration Screen for STC-0038-FitLine3D

Works both in 2D Images or in 3D Points Cloud

The sample is a 3D stereo vision system where we show how you can pick pipes from a storage.

pipes_in_a_storage — The pipes are located in 3D with Scorpion 3D Stinger technology

Standard LineFit3D with OpenCV algorithm

We do a linefit using the eight 3D points that are the center of the pipes using the OpenCV algorithm.

stc-0038-fitline3d_cvfit — The OpenCV algorithms uses all points to create the 3D Line

Robust 3D Line Fit – Theil Sen Algorithm

The robust line fit evaluate the incoming 3D points and based on a median fit assumptions it removes the outliers – in this sample it concludes the three upper points is not part of the line – which is a good conclusion.

3d fitline - incoming points — The robust line fit treats the three upper pipes as outliers – the longest / best lines in the points of the lower pipe row. The yellow points shows the incoming points

Conclusion

The Theil Sen algorithm for line fit is a good addition to the reliable 3D tools of Scorpion Vision Software. The robust median will help remove up 29.3% of the outliers and still make a good estimate. This feature will help make applications reliable. It also helps us to be significant better than OpenCV which is a requirement for us 🙂

3d fitline in 3d model — The 3D fitted line in the Scorpion 3D View

There is also a 2D version of this algorithm implemented as a Scorpion Tool Component – STC-0040 FitLine2D. This component can be used to locate a line in a noisy environment.

A large range of Scorpion Tool Components are available to Scorpion Vision Partners and users holding a Scorpion Vision SDK Licence.