Swift - AVFoundation捕捉图像方向

Question

我有一个自定义相机，可以以纵向模式拍照。

我的问题是，如果我尝试在横向模式下拍照并保存它，那么照片仍然以纵向模式保存。

我有这个函数来设置预览层：

 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中调用这个方法（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)
}

并使用此扩展：

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)
        }
    }
}

只要我拍摄肖像模式照片，一切都正常，但当我将手机旋转以拍摄横向照片时，照片仍然是以纵向拍摄的。

这是我第一次使用自定义相机，我真的不知道从哪里开始修复它... 如果有人能帮忙，我会非常感激。

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以下内容：

    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)
        }
    }
}

这个图像在预览时显示的方向是正确的，但当我保存它时，它变成了纵向。

- Marco

---

https://dev59.com/wGQo5IYBdhLWcg3wiv_A#69580115 - YodagamaHeshan

Answer 1

在调用capturePhoto()之前，您需要运行以下代码：

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

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

- adamfowlerphoto

---

谢谢您的答案，我已经完全按照苹果的建议改变了我的代码。以下是示例代码链接：https://developer.apple.com/library/content/samplecode/AVCam/Listings/Swift_AVCam_CameraViewController_swift.html#//apple_ref/doc/uid/DTS40010112-Swift_AVCam_CameraViewController_swift-DontLinkElementID_15 - Marco

AVCam是我基于其进行照片捕获的。你应该在那段代码中看到videoOrientation的设置。 - adamfowlerphoto

我明白了，你的答案确实是正确的。我只是想分享一下链接，以防有人需要它。但我想我可以接受这个答案。 - Marco

Answer 2

我曾遇到类似问题，通过基于拍摄的照片生成新图像来解决：

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

显然，由iOS生成的图像元数据（包括方向）是不完整的，一些查看器（在我的情况下是Chrome和Safari浏览器）无法正确渲染图像。通过重新渲染，元数据似乎对所有查看器都设置正确了。

请注意，1）在我的应用程序中，我还缩小了图像（我认为这不会改变效果），并且2）我通过其他方式捕获图像（即UIImagePickerController）；不过，您仍可以尝试我的hacky修复方法。

- dr_barto

---

{btsdaf} - Marco

{btsdaf} - dr_barto

{btsdaf} - Marco

{btsdaf} - dr_barto

{btsdaf} - Marco

Answer 3

基于 dr_barto 的源代码，我为 UIImage 编写了一个扩展：

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
    }
}

- Ramis

Answer 4

Swift 4.2最新的AVFoundation捕获图像方向语法（经过测试的代码）。

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

- Hardik Thakkar