Swift如何修改从移动相机拍摄的图像中的exif信息

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我使用UIImagePickerController在我的ios应用程序中选择图像,我知道可以通过info[UIImagePickerControllerMediaMetadata]获取exif信息。但是当我通过UIImage将我的图像上传到我的服务器时,大多数exif信息都是条纹的。我想知道是否可以在Http请求中将exif信息添加到我的图像中(之后上传为jpg的图像)。如果没有,我该如何解决这个问题?我想改变Make,Model属性(换句话说,用什么设备来拍这张照片)

以下是我的代码片段:

func Tapped() {
    let myPickerController = UIImagePickerController()

    myPickerController.delegate = self
    myPickerController.sourceType = UIImagePickerControllerSourceType.Camera
    myPickerController.allowsEditing = false
    self.presentViewController(myPickerController, animated: true, completion: nil)
}
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
    let image = info[UIImagePickerControllerOriginalImage] as? UIImage
    myImageView.image = image
    UIImageWriteToSavedPhotosAlbum(image!, self, #selector(ViewController.image(_:didFinishSavingWithError:contextInfo:)), nil)
    self.dismissViewControllerAnimated(true, completion: nil)
}

func myImageUploadRequest()
{

    let myUrl = NSURL(string: "http://XXXXXX/Uploadfile")

    let request = NSMutableURLRequest(URL:myUrl!)
    request.HTTPMethod = "POST"

    let param = [
        "userId"    : "7"
    ]

    let boundary = generateBoundaryString()

    request.setValue("multipart/form-data; boundary=(boundary)", forHTTPHeaderField: "Content-Type")


    let imageData = UIImageJPEGRepresentation(myImageView.image!, 1)

    if(imageData == nil)  { return; }

    request.HTTPBody = createBodyWithParameters(param, filePathKey: "file", imageDataKey: imageData!, boundary: boundary)



    myActivityIndicator.startAnimating()

    let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
        data, response, error in

        if error != nil {
            print("error=(error)")
            return
        }

        // You can print out response object
        print("******* response = (response)")

        // Print out response body
        let responseString = NSString(data: data!, encoding: NSUTF8StringEncoding)
        print("****** response data = (responseString!)")

        do{
            let json = try NSJSONSerialization.JSONObjectWithData(data!, options: .MutableContainers) as? NSDictionary

        }catch{
            print(error)
        }


        dispatch_async(dispatch_get_main_queue(),{
            self.myActivityIndicator.stopAnimating()
            self.myImageView.image = nil
        })

    }

    task.resume()
}

func createBodyWithParameters(parameters: [String: String]?, filePathKey: String?, imageDataKey: NSData, boundary: String) -> NSData {
    let body = NSMutableData();

    if parameters != nil {
        for (key, value) in parameters! {
            body.appendString("--(boundary)
")
            body.appendString("Content-Disposition: form-data; name="(key)"

")
            body.appendString("(value)
")
        }
    }

    let filename = "test.jpg"

    let mimetype = "image/jpg"

    body.appendString("--(boundary)
")
    body.appendString("Content-Disposition: form-data; name="(filePathKey!)"; filename="(filename)"
")
    body.appendString("Content-Type: (mimetype)

")
    body.appendData(imageDataKey)
    body.appendString("
")



    body.appendString("--(boundary)--
")

    return body
}

func generateBoundaryString() -> String {
    return "Boundary-(NSUUID().UUIDString)"
}

extension NSMutableData {
    func appendString(string: String) {
        let data = string.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)
        appendData(data!)
    }
}
答案

是!最后我做了一个修改EXIF信息的技巧。首先,你可以通过UIImageJPEGRepresentation从信息[UIImagePickerControllerMediaMetadata]和没有EXIF的NSData获取EXIF信息。然后,您可以使用修改的EXIF信息创建新的NSDictionary。之后,在下面调用我的函数,你可以用修改后的EXIF获取图像NSData!

func saveImageWithImageData(data: NSData, properties: NSDictionary, completion: (data: NSData, path: NSURL) -> Void) {

    let imageRef: CGImageSourceRef = CGImageSourceCreateWithData((data as CFDataRef), nil)!
    let uti: CFString = CGImageSourceGetType(imageRef)!
    let dataWithEXIF: NSMutableData = NSMutableData(data: data)
    let destination: CGImageDestinationRef = CGImageDestinationCreateWithData((dataWithEXIF as CFMutableDataRef), uti, 1, nil)!

    CGImageDestinationAddImageFromSource(destination, imageRef, 0, (properties as CFDictionaryRef))
    CGImageDestinationFinalize(destination)

    var paths: [AnyObject] = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
    let savePath: String = paths[0].stringByAppendingPathComponent("exif.jpg")

    let manager: NSFileManager = NSFileManager.defaultManager()
    manager.createFileAtPath(savePath, contents: dataWithEXIF, attributes: nil)

    completion(data: dataWithEXIF,path: NSURL(string: savePath)!)

    print("image with EXIF info converting to NSData: Done! Ready to upload! ")

}
另一答案

使用和mergind来自其他帖子的一些信息,我在Swift中使用Dictionary来解决问题。我在AVCapturePhoto的AVFounfation回调的captureOutput中使用它:

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] = "<whatever you want to write>"

    metadataAttachments[kCGImagePropertyExifDictionary as String] = exifData
    }

}

之后“metadataAttachments”用于构建最终图像(在我的例子中使用CGImageDestinationAddImage)

它似乎工作(尝试在使用Swift 4.0的项目构建中)

希望它可以帮助!

另一答案

SWIFT 3

如果您正在捕获视频并获取CMSampleBuffer,则可以使用更新EXIF元数据的方法。在iOS9的情况下,我没有得到DateTimeOriginal,虽然在iOS10中DataTimeOriginal已经存在。因此我不得不添加几个额外的键值。

self.stillCameraOutput.captureStillImageAsynchronously(from: connectionVideo) { (sampleBuffer, err) in
        if let err = err {
            blockCompletion(nil, err as NSError?)
        }
        else {
            if let sampleBuffer = sampleBuffer {
                let rawMetadata = CMCopyDictionaryOfAttachments(nil, sampleBuffer, CMAttachmentMode(kCMAttachmentMode_ShouldPropagate))
                let metadata = CFDictionaryCreateMutableCopy(nil, 0, rawMetadata) as NSMutableDictionary

                let exifData = metadata.value(forKey: "{Exif}") as? NSMutableDictionary

                print("EXIF DATA: (exifData)")

                if let dateTime = exifData?["DateTimeOriginal"] as? String {
                    print("DateTime exists (dateTime)")
                }
                else {
                    exifData?.setValue(Date().exifDate(), forKey: "DateTimeOriginal")
                }

                if let dateTime = exifData?["DateTimeDigitized"] as? String {
                    print("DateTime exists (dateTime)")
                }
                else {
                    exifData?.setValue(Date().exifDate(), forKey: "DateTimeDigitized")
                }

                metadata.setValue(exifData, forKey: "{Exif}")

                CMSetAttachments(sampleBuffer, metadata as CFDictionary, CMAttachmentMode(kCMAttachmentMode_ShouldPropagate))

                let rawMetadata2 = CMCopyDictionaryOfAttachments(nil, sampleBuffer, CMAttachmentMode(kCMAttachmentMode_ShouldPropagate))
                let metadata2 = CFDictionaryCreateMutableCopy(nil, 0, rawMetadata2) as NSMutableDictionary

                let exifData2 = metadata2.value(forKey: "{Exif}") as? NSMutableDictionary

                print("EXIF DATA: (exifData2)")

                if let dataImage = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(sampleBuffer) {
                    blockCompletion(dataImage, nil)
                }
                else {
                    blockCompletion(nil, nil)
                }
            }
            else {
                blockCompletion(nil, nil)
            }
        }
    }

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