A little google magic and it showed me the answer to your question.
If your question is "How to detect the the direction of the scroll?" well it was already answered
here is the link
Edit::
in iCarousel.h
show - (void)didPan:(UIPanGestureRecognizer *)panGesture;
then create a subclass of iCarousel.
in the iCarouselsubclass.m
:
-(void)didPan:(UIPanGestureRecognizer *)panGesture{
// check direction here using values for super didPan method
[super didPan:panGesture]; // do not call if you dont want to scroll the view
}