How can i measure a vector's size, angle and direction that i found using Farneback's method?

For this simple example of Farneback's method, how can i measure the vector's characteristics?

Answer 1

[Swarooph]

The flow variable output from estimateFlow function is of type opticalFlow and has all the information. You can access them using the dot (.) operator.

For e.g.

vx = flow.Vx;
vy = flow.Vy;
or = flow.Orientation;
mag = flow.Magnitude;

[Manasi Pathade]

Which equation is used to compute flow.Orientation?

Is it atan2 or atan2d?

I wanted to know, what are the reference directions (0,90,180,270) in OpticalFlow?

Please help