在imageView中拉伸图像以响应UISlider

i have placed a image in a imageView in viewController's view in a view based project. i used IBoutlet to create a imageView and pasted a image in it .similarly i placed a UISlider too. my image is something like a room window with horizontal bars.the distance btn the bars is very minute. My requirement is "as i move the UISlider the image should get zoomed in the centre so that the gap between the bars gets maximized. At the end of the slide the image should be visible with only one or two horizontal bars"i have placed a image in a imageView in viewCon