Android App Tracking Points: Video.calcopticalflow(...) Method Not Working Properly?

I am currently trying to create an Android App using OpenCV that allows the user to track points of moving objects using the smartphone camera. An analogous code in C++ that does e

Solution 1:

SOLVED:

I changed:

prevGray = nextGray;prev2D = next2D;

to:

  nextGray.copyTo(prevGray);
  next2D.copyTo(prev2D);

I hope it helps anyone encountering similar problems.