Swift how to modify exif info in images taken from mobile camera

Question

I use UIImagePickerController to pick images in my iOS App and I know exif info can be got by info[UIImagePickerControllerMediaMetadata]. But when

Answer 1

using and mergind some info from other posts, I approached problem using Dictionary in Swift. I used it in captureOutput of AVFounfation callback for AVCapturePhoto:

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

    //retrieve exif information
    var photoFormatDescription: CMFormatDescription?
    CMVideoFormatDescriptionCreateForImageBuffer(kCFAllocatorDefault, photoPixelBuffer, &photoFormatDescription)

    var metadataAttachments: Dictionary = photo.metadata as Dictionary

    if var exifData = metadataAttachments["{Exif}"] as? [String: Any] {
        exifData[kCGImagePropertyExifUserComment as String] = ""

    metadataAttachments[kCGImagePropertyExifDictionary as String] = exifData
    }

}

After that "metadataAttachments" is used to build final image (using CGImageDestinationAddImage in my case)

It seems to work (tried in a project build with Swift 4.0)

Hope it can help!