private Bitmap getThreeFrameDifference(Bitmap frame)
{
if (lastFrame == null || lastButOneFrame == null)
{
return null;
}
Difference filterPrevious = new Difference(lastButOneFrame);
Bitmap differenceBitmapPrevious = filterPrevious.Apply(lastFrame);
Difference filterNext = new Difference(lastFrame);
Bitmap differenceBitmapNext = filterNext.Apply(frame);
Intersect intersectionFilter = new Intersect(differenceBitmapPrevious);
Bitmap threeFrameDifferenceBitmap = intersectionFilter.Apply(differenceBitmapNext);
return threeFrameDifferenceBitmap;
}
