swift - making an image the full size of a scrollview -

i have set image background in scrollview can zoom in pan around it, however, when image zoomed out creates white borders left , right of image can assume scrollview margins.

any way rid of these image fills screen?

edit: here picture show mean, white bars along sides of grey background edges of scrollview, want grey background fill screen apart iad bar. http://i.stack.imgur.com/qx0kk.png

many thanks!

// 1          let image = uiimage(named: "photo1")!          imageview = uiimageview(image: image)          imageview.frame = cgrect(origin: cgpointmake(0, 0), size:image.size)                    // 2          scrollview.addsubview(imageview)          scrollview.contentsize = image.size                    // 3          var doubletaprecognizer = uitapgesturerecognizer(target: self, action: "scrollviewdoubletapped:")          doubletaprecognizer.numberoftapsrequired = 2          doubletaprecognizer.numberoftouchesrequired = 1          scrollview.addgesturerecognizer(doubletaprecognizer)                    // 4          let scrollviewframe = scrollview.frame          let scalewidth = scrollviewframe.size.width / scrollview.contentsize.width          let scaleheight = scrollviewframe.size.height / scrollview.contentsize.height          let minscale = min(scalewidth, scaleheight);          scrollview.minimumzoomscale = minscale;                    // 5          scrollview.maximumzoomscale = 1.0          scrollview.zoomscale = minscale;                    // 6          centerscrollviewcontents()    }            func centerscrollviewcontents() {          let boundssize = scrollview.bounds.size          var contentsframe = imageview.frame                    if contentsframe.size.width < boundssize.width {              contentsframe.origin.x = (boundssize.width - contentsframe.size.width) / 2.0          } else {              contentsframe.origin.x = 0.0          }                    if contentsframe.size.height < boundssize.height {              contentsframe.origin.y = (boundssize.height - contentsframe.size.height) / 2.0          } else {              contentsframe.origin.y = 0.0          }                    imageview.frame = contentsframe                }            func scrollviewdoubletapped(recognizer: uitapgesturerecognizer) {          // 1          let pointinview = recognizer.locationinview(imageview)                    // 2          var newzoomscale = scrollview.zoomscale * 1.5          newzoomscale = min(newzoomscale, scrollview.maximumzoomscale)                    // 3          let scrollviewsize = scrollview.bounds.size          let w = scrollviewsize.width / newzoomscale          let h = scrollviewsize.height / newzoomscale          let x = pointinview.x - (w / 2.0)          let y = pointinview.y - (h / 2.0)                    let recttozoomto = cgrectmake(x, y, w, h);                    // 4          scrollview.zoomtorect(recttozoomto, animated: true)      }            func viewforzoominginscrollview(scrollview: uiscrollview) -> uiview? {          return imageview      }            func scrollviewdidzoom(scrollview: uiscrollview) {          centerscrollviewcontents()      }

you setting min zoomscale min of width , height scales. desired, allows see entire image (aspectfit). sounds want aspectfill though, that, need use max of width , height scales.

let minscale = max(scalewidth, scaleheight);