Swift accessing EXIF Dictionary

Question

Info: Using Swift and the CGImageSourceCreateWithURL function.

I am attempting to load a file from a URL and then edit a dictionary which has all the data from that particular photo.

This is the code from the .swift file.

    let url = NSURL(string: "http://jwphotographic.co.uk/Images/1.jpg")
    let imageSource = CGImageSourceCreateWithURL(url, nil)
    let imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, nil) as Dictionary

    println(imageProperties)

    //this is an example
    let aperture = imageProperties[kCGImagePropertyGPSLatitude] as! NSNumber!

    /*
    //these are all being defined as nil
    //Load the ones from the exif data of the file
    let lensUsed = imageProperties[kCGImagePropertyExifFocalLength]
    let aperture = imageProperties[kCGImagePropertyExifApertureValue] as!
    let isoSpeed = imageProperties[kCGImagePropertyExifISOSpeedRatings] as! NSNumber
    let latitude = imageProperties[kCGImagePropertyGPSLatitude] as! NSNumber
    let longitude = imageProperties[kCGImagePropertyGPSLongitude] as! NSNumber
    let shutterSpeed = imageProperties[kCGImagePropertyExifShutterSpeedValue] as! NSNumber
    let cameraName = imageProperties[kCGImagePropertyExifBodySerialNumber] as! NSNumber
    */

    println(aperture)

Even though image properties prints all the data as would be expected, no-matter what I have attmpted to extract from the imageProperties dictionary - it is always returned as null - such as 'aperture' in the example. The imageProperties prints as;

[{TIFF}: {
     Artist = JOHN;
     Copyright = "[email protected]";
     DateTime = "2015:07:31 21:07:05";
     Make = Canon;
     Model = "Canon EOS 7D Mark II";
     ResolutionUnit = 2;
     Software = "Adobe Photoshop Lightroom 6.0 (Macintosh)";
     XResolution = 72;
     YResolution = 72;
}, {IPTC}: {
     Byline =     (
       JOHN
     );
     CopyrightNotice = etc.. etc..

I have done a lot of research and testing and I simply cannot work out what I'm doing wrong to access the elements in this dictionary - Could someone give me an example how I would set a variable as the "Model" element inside the dictionary?

Answer 1

To get to Exif parameters do the following:

    let filePath_ = "file:///Users/pfernandes/Documents/softwareDevelopment/PhotoLine/TestData/IMG_1243.JPG"
    let fileURL = NSURL(string:filePath_)
    let myImage = CGImageSourceCreateWithURL(fileURL!,nil)

    let imageDict = CGImageSourceCopyPropertiesAtIndex(myImage!, 0, nil)! as NSDictionary;
    let tiffModel_ = imageDict.value(forKey: "{TIFF}")

    let cameraMake = (tiffModel_ as AnyObject).value(forKey: kCGImagePropertyTIFFMake as String)
    let cameraModel = (tiffModel_ as AnyObject).value(forKey: kCGImagePropertyTIFFModel as String)

    let exifDict_ = imageDict.value(forKey: "{Exif}") as! NSDictionary
    let dateTimeOriginal = exifDict_.value(forKey:kCGImagePropertyExifDateTimeOriginal as String) as! NSString
    let exposure         = exifDict_.value(forKey:kCGImagePropertyExifExposureTime as String)

    print ("\(String(describing: cameraMake)) \(String(describing: cameraModel)) \(dateTimeOriginal) \(exposure!)")

Answer 2

In Swift 3.0 I found the following solution

let url = NSURL(string: "http://jwphotographic.co.uk/Images/1.jpg")
let imageSource = CGImageSourceCreateWithURL(url, nil)
let imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, nil) as Dictionary?
let exifDict = imageProperties?[kCGImagePropertyExifDictionary]

Now you can access the exif-Tags by for example

let dateTimeOriginal = exifDict?[kCGImagePropertyExifDateTimeOriginal]
Swift.print("dateTimeOriginal: \(dateTimeOriginal)")

You will get optional values and you have to test, if there are values or nil. For a list of available property constants look at the apple documentation.

Answer 3

This code will help you to obtain the date of the photo and exif

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    picker.dismiss(animated: true, completion: nil)
    if let image = info[.originalImage] as? UIImage {
        
       
        let assetURL = info[UIImagePickerController.InfoKey.referenceURL] as! NSURL
        let asset = PHAsset.fetchAssets(withALAssetURLs: [assetURL as URL], options: nil)
        guard let result = asset.firstObject else {
            return
        }

        let imageManager = PHImageManager.default()
        imageManager.requestImageData(for: result , options: nil, resultHandler:{
            (data, responseString, imageOriet, info) -> Void in
            let imageData: NSData = data! as NSData
            if let imageSource = CGImageSourceCreateWithData(imageData, nil) {
                let imageDict = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, nil)! as NSDictionary
                let exifDict_ = imageDict.value(forKey: "{Exif}") as! NSDictionary
                   let dateTimeOriginal = exifDict_.value(forKey:kCGImagePropertyExifDateTimeOriginal as String) as! NSString
               print (" exifDict : \(exifDict_)")
                print (" fecha : original \(dateTimeOriginal)")
            }
        })
        
    picker.dismiss(animated: true, completion: nil)
}