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

I came up with a code that will give a desired cropped aspect ratio, regardless of original video frame size (adapted from @Cole's answer):

func cropImage(uncroppedImage: UIImage, cropWidth: CGFloat, cropHeight: CGFloat) -> UIImage {

        let contextImage: UIImage = UIImage(cgImage: uncroppedImage.cgImage!)

        let contextSize: CGSize = contextImage.size
        var cropX: CGFloat = 0.0
        var cropY: CGFloat = 0.0
        var cropRatio: CGFloat = CGFloat(cropWidth/cropHeight)
        var originalRatio: CGFloat = contextSize.width/contextSize.height
        var scaledCropHeight: CGFloat = 0.0
        var scaledCropWidth: CGFloat = 0.0

        // See what size is longer and set crop rect parameters
        if originalRatio > cropRatio {

            scaledCropHeight = contextSize.height
            scaledCropWidth = (contextSize.height/cropHeight) * cropWidth
            cropX = (contextSize.width - scaledCropWidth) / 2
            cropY = 0

        } else {
            scaledCropWidth = contextSize.width
            scaledCropHeight = (contextSize.width/cropWidth) * cropHeight
            cropY = (contextSize.height / scaledCropHeight) / 2
            cropX = 0
        }

        let rect: CGRect = CGRect(x: cropX, y: cropY, width: scaledCropWidth, height: scaledCropHeight)

        // 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 croppedImage: UIImage = UIImage(cgImage: imageRef, scale: uncroppedImage.scale, orientation: uncroppedImage.imageOrientation)

        return croppedImage
    }

Hope it helps!