swift set image size
extension UIImage {
func imageResize (sizeChange:CGSize)-> UIImage{
let hasAlpha = true
let scale: CGFloat = 0.0 // Use scale factor of main screen
UIGraphicsBeginImageContextWithOptions(sizeChange, !hasAlpha, scale)
self.draw(in: CGRect(origin: CGPoint.zero, size: sizeChange))
let scaledImage = UIGraphicsGetImageFromCurrentImageContext()
return scaledImage!
}
}