UIScrollview使当前图像更大

I am building a scrollable gallery with 10 images. When I stop on an image, I want the current image to look little taller than the other ones on either side. How do I get the view in focus and adjust the frame ? Once the drag ends, the function scrollViewDidEndDecelerating gets called. How do I get the reference to that imageview's frame ?I am building a scrollable gallery with 10 imag