Resize image - Swift 3

// Vladimir Zhelnov - neatek.pw - Web/iOS dev
func ResizeImage(image: UIImage, targetSize: CGSize) -> UIImage {
    let size = image.size
    let widthRatio  = targetSize.width  / image.size.width
    let heightRatio = targetSize.height / image.size.height

    var newSize: CGSize
    if(widthRatio > heightRatio) {
        newSize = CGSize(width: size.width * heightRatio, height: size.height * heightRatio)
    } else {
        newSize = CGSize(width: size.width * widthRatio,  height: size.height * widthRatio)
    }

    let rect = CGRect(x: 0, y: 0, width: newSize.width, height: newSize.height)
    UIGraphicsBeginImageContextWithOptions(newSize, false, 1.0)
    image.draw(in: rect)
    let newImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return newImage!
}
// usage: let littleImage = ResizeImage(image: chosenImage, targetSize: CGSize(width: 800, height: 500))