Cross-correlation analysis

We could try to quantify the motion of the signal in the different channels by a cross-correlation analysis of the line profile at different time-points, as this could give as a "dx" from one time point to the next.

Probably we should have a "dt" parameter for this as the motion of directly subsequent time-points may not be as obvious, and be more obvious if we increase dt a bit.

Performing this analysis also on the membrane channel could cell us whether this also moves, which could be indicative of cell movement.