How to generate an UIImage from AVCapturePhoto with correct orientation?

Question

I am calling AVFoundation\'s delegate method to handle a photo capture, but I am having difficulty converting the AVCapturePhoto it generates into

Answer 1

I've had success doing this:

func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {

        let cgImage = photo.cgImageRepresentation()!.takeRetainedValue()
        let orientation = photo.metadata[kCGImagePropertyOrientation as String] as! NSNumber
        let uiOrientation = UIImage.Orientation(rawValue: orientation.intValue)!
        let image = UIImage(cgImage: cgImage, scale: 1, orientation: uiOrientation)

}

It's based on what Apple mention in their docs:

Each time you access this method, AVCapturePhoto generates a new CGImageRef. When backed by a compressed container (such as HEIC), the CGImageRepresentation is decoded lazily as needed. When backed by an uncompressed format such as BGRA, it is copied into a separate backing buffer whose lifetime is not tied to that of the AVCapturePhoto. For a 12 megapixel image, a BGRA CGImage represents ~48 megabytes per call. If you only intend to use the CGImage for on-screen rendering, use the previewCGImageRepresentation instead. Note that the physical rotation of the CGImageRef matches that of the main image. Exif orientation has not been applied. If you wish to apply rotation when working with UIImage, you can do so by querying the photo's metadata[kCGImagePropertyOrientation] value, and passing it as the orientation parameter to +[UIImage imageWithCGImage:scale:orientation:]. RAW images always return a CGImageRepresentation of nil. If you wish to make a CGImageRef from a RAW image, use CIRAWFilter in the CoreImage framework.