I'm trying to add GPS metadata to the image taken with AVFoundation in swift. I have the code pasted below but it doesn't work yet. Where is my mistake?
let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(imageDataSampleBuffer)
let imgDataProvider = CGDataProviderCreateWithCFData(imageData);
let imageRef = CGImageCreateWithJPEGDataProvider(imgDataProvider, nil, true, .RenderingIntentDefault)
let properties = self.getImageProperties(imageData)
let mutableDictionary: NSMutableDictionary = NSMutableDictionary(dictionary: properties)
mutableDictionary.setValue(self.getGPSDictionary(), forKey: kCGImagePropertyGPSDictionary as String)
let newImageData = CFDataCreateMutable(nil, 0)
let type = UTTypeCreatePreferredIdentifierForTag(kUTTagClassMIMEType, "image/jpg" as CFString, kUTTypeImage)
let destination = CGImageDestinationCreateWithData(newImageData, (type?.takeRetainedValue())!, 1, nil)
CGImageDestinationAddImage(destination!, imageRef!, mutableDictionary)
CGImageDestinationFinalize(destination!)
let newImage = newImageData
getImageProperties method:
private func getImageProperties(data: NSData) -> NSDictionary {
let imageSourceRef = CGImageSourceCreateWithData(data, nil);
let properties = CGImageSourceCopyPropertiesAtIndex(imageSourceRef!, 0, nil)
let props = properties
return props!
}
getGPSDictionary method:
private func getGPSDictionary() -> NSDictionary {
let dictionary = [kCGImagePropertyGPSLatitude as String :"54",kCGImagePropertyGPSLongitude as String :"23"]
return dictionary
}
Yes, i know that coordinates are hardcoded so far but important for now is to make it working, i will update location.
This is how I did it. This worked on Swift 2.2 iOS 9.2
@IBAction func shutter(sender: AnyObject) {
let connection = imageOutput.connectionWithMediaType(AVMediaTypeVideo)
// set the orientation
if connection.supportsVideoOrientation {
connection.videoOrientation = currentVideoOrientation()
}
imageOutput.captureStillImageAsynchronouslyFromConnection(connection) {
(sampleBuffer: CMSampleBuffer!, error: NSError!) -> Void in
if sampleBuffer != nil {
let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(sampleBuffer)
// get the old EXIF
let oldEXIF = self.getEXIFFromImage(imageData)
// add gps info to the old exif
let newEXIF = self.addGPSToEXIF(oldEXIF, new: self.getGPSDictionaryForLocation(Genba.sharedInstance.gps.currentLocation))
// resize the image to desired
let resized = self.resizeNSDataImage(imageData, newSize: Genba.sharedInstance.imageSize)
// attach the new exif to the resized image
let attached = self.attachEXIFtoImage(resized, EXIF: newEXIF)
// save the file to the camera roll and inside the app
self.saveFile(attached)
} else {
debugPrint(self.n,#line,"Error capturing photo \(error.localizedDescription)")
}
}
}
The helper functions are here
// combine exif dictionaries
func addGPSToEXIF(old:NSDictionary, new:NSDictionary) -> NSDictionary {
old.setValue(new, forKey: kCGImagePropertyGPSDictionary as String)
return old
}
// get an NSDictionary from an image
func getEXIFFromImage(image:NSData) -> NSDictionary {
let imageSourceRef = CGImageSourceCreateWithData(image, nil);
let currentProperties = CGImageSourceCopyPropertiesAtIndex(imageSourceRef!, 0, nil)
let mutableDict = NSMutableDictionary(dictionary: currentProperties!)
return mutableDict
}
// Attach EXIF DIctionary data to an image
func attachEXIFtoImage(image:NSData, EXIF:NSDictionary) -> NSData {
let imageDataProvider:CGDataProviderRef = CGDataProviderCreateWithCFData(image)!
let imageRef:CGImageRef = CGImageCreateWithJPEGDataProvider(imageDataProvider, nil, true, .RenderingIntentDefault)!
let newImageData:CFMutableDataRef = CFDataCreateMutable(nil, 0)
let type = UTTypeCreatePreferredIdentifierForTag(kUTTagClassMIMEType, "image/jpg" as CFString, kUTTypeImage)
let destination:CGImageDestinationRef = CGImageDestinationCreateWithData(newImageData, (type?.takeRetainedValue())!, 1, nil)!
CGImageDestinationAddImage(destination, imageRef, EXIF as CFDictionaryRef)
CGImageDestinationFinalize(destination)
return newImageData as NSData
}
// save file within app with EXIF
func saveFile(image: NSData) {
// Saves the file out
let dataPath = Genba.sharedInstance.userdata_save_folder
let fileExists = dataPath.checkResourceIsReachableAndReturnError(nil)
if fileExists {
let formatter = NSDateFormatter()
formatter.dateFormat = "Y-M-dd_HH-mm-ss"
let time = formatter.stringFromDate(NSDate())
let savefilepath = dataPath.URLByAppendingPathComponent(time+".jpg")
let result = image.writeToURL(savefilepath, atomically: false)
if result {
savePhotoToLibraryWithURL(savefilepath)
} else {
debugPrint(n,#line,"failed to save")
}
}
}
// resize image from NSData
func resizeNSDataImage (inputImage:NSData, newSize:CGSize) -> NSData {
var smallerImage:NSData? = nil
let image = UIImage(data: inputImage)
UIGraphicsBeginImageContext(newSize)
image!.drawInRect(CGRect(origin: CGPointZero, size: newSize))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
smallerImage = UIImageJPEGRepresentation(newImage, 1)
return smallerImage!
}
func savePhotoToLibraryWithURL(image: NSURL) {
let photoLibrary = PHPhotoLibrary.sharedPhotoLibrary()
photoLibrary.performChanges({
PHAssetChangeRequest.creationRequestForAssetFromImageAtFileURL(image)
}) { (success: Bool, error: NSError?) -> Void in
if success {
} else {
print(self.n,#line,"Error writing to photo library: \(error!.localizedDescription)")
}
}
}
Save image through ALAssetsLibrary:
let imgDataProvider = CGDataProviderCreateWithCFData(imageData);
let imageRef = CGImageCreateWithJPEGDataProvider(imgDataProvider, nil, true, .RenderingIntentDefault)
let library = ALAssetsLibrary()
library.writeImageToSavedPhotosAlbum(imageRef, metadata:mutableDictionary as [NSObject : AnyObject], completionBlock:nil)
