swift uiimage size code example

Example 1: 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!
    }

}

Example 2: swift decrease image size

let actualHeight:CGFloat = image.size.height
let actualWidth:CGFloat = image.size.width
let imgRatio:CGFloat = actualWidth/actualHeight
let maxWidth:CGFloat = 1024.0
let resizedHeight:CGFloat = maxWidth/imgRatio
let compressionQuality:CGFloat = 0.5

let rect:CGRect = CGRect(x: 0, y: 0, width: maxWidth, height: resizedHeight)
UIGraphicsBeginImageContext(rect.size)
image.draw(in: rect)
let img: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
let imageData:Data = UIImageJPEGRepresentation(img, compressionQuality)!
UIGraphicsEndImageContext()

return UIImage(data: imageData)!