Firefly Eindhoven - Remaining Sensors

Optical flow

Optical flow refers to estimation of apparent velocities of certain objects in an image. This is done by measuring the optical flow of each frame using which velocities of objects can be estimated. It is 2D vector field where each vector is a displacement vector showing the movement of points from first frame to second. By estimating the flow of points in a frame, the velocity of the moving camera can be calculated.

Working Principle If [math]\displaystyle{ I(x,y,t) }[/math] is a pixel in an image then after some time dt, as the pixel moves some distance dx and dy then as the pixel intensity is consistent, it can be said that;

[math]\displaystyle{ I(x,y,t) = I(x+dx, y+dy, t+dt) }[/math]

Using taylor series, it is possible to write

<math>