How to write Exif data to image in Swift with lat long

This could be from your destination definition.

This worked for me

(...)
    let source                  =   CGImageSourceCreateWithData(jpgData as CFData, nil)

    let finalData               =   NSMutableData()

    let destination             =   getDestination(finalData:finalData, source:source!)

(...)

// Note that :
// NSMutableData type variable will be cast to CFMutableData
// 
fileprivate func getDestination(finalData:CFMutableData, source:CGImageSource)->CGImageDestination?{
    guard let destination = CGImageDestinationCreateWithData(finalData,
                                                             CGImageSourceGetType(source)!,
                                                             1,
                                                             nil)else{return nil}
    return destination
}

Please check this below answer. you got error due to nil value on EXIFDictionary and GPSDictionary

 var image = info[UIImagePickerControllerOriginalImage] as! UIImage
 let jpeg = UIImageJPEGRepresentation(image, 1.0)
 var source: CGImageSource? = nil
 source = CGImageSourceCreateWithData((jpeg as CFData?)!, nil)
 let metadata = CGImageSourceCopyPropertiesAtIndex(source!, 0, nil) as? [AnyHashable: Any]
 var metadataAsMutable = metadata
 var EXIFDictionary = (metadataAsMutable?[(kCGImagePropertyExifDictionary as String)]) as? [AnyHashable: Any]
 var GPSDictionary = (metadataAsMutable?[(kCGImagePropertyGPSDictionary as String)]) as? [AnyHashable: Any]

 if !(EXIFDictionary != nil) {
       EXIFDictionary = [AnyHashable: Any]()
    }
  if !(GPSDictionary != nil) {
       GPSDictionary = [AnyHashable: Any]()
   }

   GPSDictionary![(kCGImagePropertyGPSLatitude as String)] = 30.21313
   GPSDictionary![(kCGImagePropertyGPSLongitude as String)] = 76.22346
   EXIFDictionary![(kCGImagePropertyExifUserComment as String)] = "Hello Image"

   let UTI: CFString = CGImageSourceGetType(source!)!
   let dest_data = NSMutableData()
   let destination: CGImageDestination = CGImageDestinationCreateWithData(dest_data as CFMutableData, UTI, 1, nil)!
   CGImageDestinationAddImageFromSource(destination, source!, 0, (metadataAsMutable as CFDictionary?))
            CGImageDestinationFinalize(destination)