swift - How to take clear screenShot IOS -

i working on ios application in taking clear screen shot required i've tried

func captureview() -> uiimage {         //hide controls if needed         let rect: cgrect = self.imageview.frame         uigraphicsbeginimagecontext(rect.size)         let context: cgcontextref = uigraphicsgetcurrentcontext()!         self.view.layer.renderincontext(context)         let img: uiimage = uigraphicsgetimagefromcurrentimagecontext()         uigraphicsendimagecontext()         return img     } 

but quality of image not good. please suggest me it.

change line

uigraphicsbeginimagecontext(rect.size) 

to

uigraphicsbeginimagecontextwithoptions(rect.size, false, 0.0);