Swift - AVFoundation 捕获图像方向

Question

我有一个自定义相机，它以纵向模式拍照。

我的问题是，如果我尝试以横向拍摄照片并保存，那么照片仍以纵向模式保存。

我有这个功能来设置预览层：

 static func setupPreviewLayer(view: UIView) {
    cameraPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
    cameraPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
    switch UIDevice.current.orientation {
    case .portrait:
        cameraPreviewLayer?.connection?.videoOrientation = 
       AVCaptureVideoOrientation.portrait
    case .portraitUpsideDown:
        cameraPreviewLayer?.connection?.videoOrientation = 
          AVCaptureVideoOrientation.portraitUpsideDown
    case .landscapeLeft:
        cameraPreviewLayer?.connection?.videoOrientation =
        AVCaptureVideoOrientation.landscapeLeft
    case .landscapeRight:
        cameraPreviewLayer?.connection?.videoOrientation = 
         AVCaptureVideoOrientation.landscapeRight
    default:
        cameraPreviewLayer?.connection?.videoOrientation = 
         AVCaptureVideoOrientation.portrait
    }
    cameraPreviewLayer?.frame = view.frame
    view.layer.insertSublayer(cameraPreviewLayer!, at: 0)
}

我在 viewWillAppear 中称之为（我认为这不是正确的做法）。

然后我拍照：

@IBAction func takePhotoBtnPressed(_ sender: Any) {
    let settings = AVCapturePhotoSettings()
    useFlash(settings: settings)
    settings.isAutoStillImageStabilizationEnabled = true
    CustomCamera.photoOutput?.capturePhoto(with: settings, delegate: self)
}

并使用这个扩展：

extension FishCameraVC: AVCapturePhotoCaptureDelegate {
func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
    if let imageData = photo.fileDataRepresentation() {
        image = UIImage(data: imageData)


          performSegue(withIdentifier: "ShowTakenPhoto", sender: nil)
        }
    }
}

只要我拍摄纵向模式的照片，一切正常，但是当我旋转手机拍摄横向照片时，照片仍然是纵向拍摄的。

这是我第一次使用定制相机，我真的不知道从哪里开始解决这个问题...... 如果有人可以提供帮助，我将不胜感激。

谢谢！

---------------更新 我已经添加了这个功能：

func managePhotoOrientation() -> UIImageOrientation {
    var currentDevice: UIDevice
    currentDevice = .current
    UIDevice.current.beginGeneratingDeviceOrientationNotifications()
    var deviceOrientation: UIDeviceOrientation
    deviceOrientation = currentDevice.orientation

    var imageOrientation: UIImageOrientation!

    if deviceOrientation == .portrait {
        imageOrientation = .up
        print("Device: Portrait")
    }else if (deviceOrientation == .landscapeLeft){
        imageOrientation = .left
        print("Device: LandscapeLeft")
    }else if (deviceOrientation == .landscapeRight){
        imageOrientation = .right
        CustomCamera.cameraPreviewLayer?.connection?.videoOrientation = .landscapeRight
        print("Device LandscapeRight")
    }else if (deviceOrientation == .portraitUpsideDown){
        imageOrientation = .down
        print("Device PortraitUpsideDown")
    }else{
       imageOrientation = .up
    }
    return imageOrientation
}

并将我的扩展名更改为：

    extension FishCameraVC: AVCapturePhotoCaptureDelegate {
    func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
        if let imageData = photo.fileDataRepresentation() {
            image = UIImage(data: imageData)
            let dataProvider  = CGDataProvider(data: imageData as CFData)
            let cgImageRef = CGImage(jpegDataProviderSource: dataProvider!, decode: nil, shouldInterpolate: true, intent: .defaultIntent)
            self.image = UIImage(cgImage: cgImageRef!, scale: 1.0, orientation: imageOrientation!)
            performSegue(withIdentifier: "ShowTakenPhoto", sender: nil)
        }
    }
}

图像以正确的方向显示在预览中，但是当我保存它时它会变成纵向...

Answer 1

在调用 capturePhoto() 之前需要运行以下代码

if let photoOutputConnection = CustomCamera.photoOutput.connection(with: AVMediaType.video) {
    photoOutputConnection.videoOrientation = videoDeviceOrientation
}

您可以使用 managePhotoOrientation() 函数来获取 videoDeviceOrientation。

Answer 2

我遇到了类似的问题，并通过根据拍摄的照片生成新图像来解决它：

UIGraphicsBeginImageContextWithOptions(image.size, false, image.scale)
image.draw(in: CGRect(origin: .zero, size: image.size))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()

显然，iOS 生成的图像元数据（包括方向）不完整，一些查看器（在我的情况下为 Chrome 和 Safari 浏览器）无法正确呈现图像。通过重新渲染，元数据似乎已为所有查看者正确设置。

请注意，1) 在我的应用程序中，我还缩小了图像的尺寸（但我认为这不会改变效果）和 2) 我通过其他方式捕获图像（即UIImagePickerController）；不过，你可以试试我的 hacky fix。

Answer 3

用于 AVFoundation 捕获图像方向的 Swift 4.2 最新语法（测试代码）。

UIGraphicsBeginImageContextWithOptions((image?.size)!, false, (image?.scale)!)
image?.draw(in: CGRect(origin: .zero, size: (image?.size)!))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()

Answer 4

基于dr_barto源代码我为UIImage写了一个扩展：

extension UIImage {
    var orientationCorrectedImage: UIImage? {
        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
        self.draw(in: CGRect(origin: .zero, size: self.size))
        let result = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return result
    }
}