Why touches Ended not being detected in pinch movement?

Question

I am doing the pinch swipe in UIScrollView. I have subclassed UIScrollView and for single tap and double tap everything is working fine. Even The touches began is working for swipe but not touchesEnded. When i do the pinch movement, whether inside/outside it appeas to move like a normal swipe. When I just tap on with double fingers also, it gives [touches count] =2. Should I do some extra steps before writing my code?

What I am doing:I have loaded 25 images in this UIScrollView and when i pinch move, after calculating the distance i want it to load another images:=this is the code part.