Cropping image with Swift and put it on center position

Question

In Swift programming , how do you crop an image and put it on the center afterwards?

This is what I\'ve got so far ... I\'ve successfully crop the image but I want t

Answer 1

Working Swift 3 example

extension UIImage {

    func crop(to:CGSize) -> UIImage {
        guard let cgimage = self.cgImage else { return self }

        let contextImage: UIImage = UIImage(cgImage: cgimage)

        let contextSize: CGSize = contextImage.size

        //Set to square
        var posX: CGFloat = 0.0
        var posY: CGFloat = 0.0
        let cropAspect: CGFloat = to.width / to.height

        var cropWidth: CGFloat = to.width
        var cropHeight: CGFloat = to.height

        if to.width > to.height { //Landscape
            cropWidth = contextSize.width
            cropHeight = contextSize.width / cropAspect
            posY = (contextSize.height - cropHeight) / 2
        } else if to.width < to.height { //Portrait
            cropHeight = contextSize.height
            cropWidth = contextSize.height * cropAspect
            posX = (contextSize.width - cropWidth) / 2
        } else { //Square
            if contextSize.width >= contextSize.height { //Square on landscape (or square)
                cropHeight = contextSize.height
                cropWidth = contextSize.height * cropAspect
                posX = (contextSize.width - cropWidth) / 2
            }else{ //Square on portrait
                cropWidth = contextSize.width
                cropHeight = contextSize.width / cropAspect
                posY = (contextSize.height - cropHeight) / 2
            }
        }

        let rect: CGRect = CGRect(x: posX, y: posY, width: cropWidth, height: cropHeight)
        // Create bitmap image from context using the rect
        let imageRef: CGImage = contextImage.cgImage!.cropping(to: rect)!

        // Create a new image based on the imageRef and rotate back to the original orientation
        let cropped: UIImage = UIImage(cgImage: imageRef, scale: self.scale, orientation: self.imageOrientation)

        UIGraphicsBeginImageContextWithOptions(to, true, self.scale)
        cropped.draw(in: CGRect(x: 0, y: 0, width: to.width, height: to.height))
        let resized = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return resized!
    }
}

Answer 2

You can just crop using:

let croppedImage = yourImage.cgImage.cropping(to:rect)