从相机捕获的iphone图像自动旋转Swift

Question

以编程方式，我在我的应用程序中从我的相机捕获了图像。 它已被很好地获取，但是当我转移到另一个视图时，查看并关闭该视图，当时我的图像我想旋转为横向。 我从相机捕捉图像。 当我从照片库中获取图像时，没有发现任何问题。

下图是我的原图。 截屏

我想旋转图像。 截屏

代码如下：

var captureSesssion : AVCaptureSession!
var cameraOutput : AVCapturePhotoOutput!
var previewLayer : AVCaptureVideoPreviewLayer!
var device:AVCaptureDevice!
var currentViewControl = UIViewController()
var tempImageHolder = UIImage()

func beginCamera(_ targetView: UIView, _ currentVC: UIViewController) 
{ 
    currentViewControl = currentVC
    // Do any additional setup after loading the view, typically from a nib.
    captureSesssion = AVCaptureSession()
    captureSesssion.sessionPreset = AVCaptureSession.Preset.photo
    cameraOutput = AVCapturePhotoOutput()

    if #available(iOS 11.1, *) {
        let availableDevices = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera, .builtInTelephotoCamera, .builtInTrueDepthCamera], mediaType: AVMediaType.video, position: .back).devices
        device = availableDevices.first
    } else {
        // Fallback on earlier versions
        device = AVCaptureDevice.default(for: .video)!
    }

    if let input = try? AVCaptureDeviceInput(device: device!) {
        if (captureSesssion.canAddInput(input)) {
            captureSesssion.addInput(input)
            if (captureSesssion.canAddOutput(cameraOutput)) {
                captureSesssion.addOutput(cameraOutput)
                let connection = cameraOutput.connection(with: AVFoundation.AVMediaType.video)
                connection?.videoOrientation = .portrait
                previewLayer = AVCaptureVideoPreviewLayer(session: captureSesssion)
                self.previewLayer.frame = targetView.frame
                self.previewLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
                //setOutputOrientation()
                targetView.layer.addSublayer(previewLayer)
                captureSesssion.startRunning()
            }
        } else {
            print("issue here : captureSesssion.canAddInput")
        }
    } else {
        print("some problem here")
    }
    previewLayer?.frame.size = targetView.frame.size
}

   func image(_ image: UIImage, didFinishSavingWithError error: Error?, contextInfo: UnsafeRawPointer) {
    if let error = error {
        // we got back an error!
        let alert = UIAlertController(title: "Error", message: error.localizedDescription, preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "OK", style: .default))
        currentViewControl.present(alert, animated: true)
    } else {
    }}


 func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
    let imageData = photo.fileDataRepresentation()
    let imageSize: Int = imageData!.count
    print(imageSize)
    tempImageHolder = UIImage(data: (imageData! as NSData) as Data)!
    //When use this below line works fine when take images from left landscape, but when take images from right landscape image not show properly screen shot below:
    tempImageHolder = UIImage(cgImage: tempImageHolder.cgImage!, scale: tempImageHolder.scale, orientation: .up)
    }
}

从左侧风景拍摄图像时：

输入：屏幕截图

输出：屏幕截图

当从正确的风景拍摄图像时

输入：屏幕截图

输出：屏幕截图

UIImage(cgImage: tempImageHolder.cgImage!, scale: tempImageHolder.scale, orientation: .up)

当从左侧风景拍摄图像时使用上面这条线工作正常，但是当从右侧风景图像拍摄图像时无法正确显示屏幕截图

有人可以向我解释如何旋转图像。 任何帮助将不胜感激。

提前致谢。

Answer 1

这是一个非常烦人的问题，我真的不敢相信 AVFoundation 对我们来说没有什么更容易的。 但是在我的应用程序中，我通过保持当前设备方向来做到这一点。 当照片输出带有图像时，使用方向旋转图像以确保所有图像都向上。

class MyViewController: UIViewController {

    var currentOrientation: UIDeviceOrientation = .portrait

    override func viewDidLoad() {
        NotificationCenter.default.addObserver(self, selector: #selector(orientationChanged), name: UIDevice.orientationDidChangeNotification, object: nil)
    }

    @objc func orientationChanged() {
        currentOrientation = UIDevice.current.orientation
    }

    func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
        guard let img = photo.cgImageRepresentation()?.takeUnretainedValue() else { return }
        let temp = CIImage(cgImage: img)
        var ciImage = temp;
        switch currentOrientation {
            case .portrait:
                ciImage = temp.oriented(forExifOrientation: 6)
            case .landscapeRight:
                ciImage = temp.oriented(forExifOrientation: 3)
            case .landscapeLeft:
                ciImage = temp.oriented(forExifOrientation: 1)
            default:
                break
        }

        guard let cgImage = CIContext(options: nil).createCGImage(ciImage, from: ciImage.extent) else { return }
        let fixedImage = UIImage(cgImage: cgImage)
    }


}

最后，根据您的需要使用fixedImage 。 请注意，我订阅了通知中心以了解方向的变化。

Answer 2

enum CGImageOrientation {
case up
case down
case left
case right
case upMirrored
case downMirrored
case leftMirrored
case rightMirrored
}

  extension CGImage {
   func orientImage(_ imageOrientation: CGImageOrientation) -> 
   CGImage? {
    return orientImageWithTransform(imageOrientation).0
 }

func orientImageWithTransform(_ imageOrientation: CGImageOrientation) -> (CGImage?, CGAffineTransform) {

    var transform = CGAffineTransform.identity
    if imageOrientation == .up { return (self.copy(), transform)}


    let size = CGSize(width: width, height: height)
    let newSize = [.left,.leftMirrored, .right, .rightMirrored].contains(imageOrientation)
        ? CGSize(width: size.height, height: size.width) : size

    // Guard that we have color space and core graphics context.
    guard let colorSpace = self.colorSpace,
        // New graphic context uses transformed width and height.
        let ctx = CGContext(data: nil, width: Int(newSize.width), height: Int(newSize.height),
                            bitsPerComponent: self.bitsPerComponent, bytesPerRow: 0,
                            space: colorSpace, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)
        else { return (nil, transform)}

    // OK, now the actual work of constructing transform and creating new image.
    switch imageOrientation {
    case .down, .downMirrored:
        transform = transform.translatedBy(x: size.width, y: size.height)
        transform = transform.rotated(by: CGFloat.pi)
        break
    case .left,.leftMirrored:
        transform = transform.translatedBy(x: size.height, y: 0)
        transform = transform.rotated(by: CGFloat.pi/2)
        break
    case .right, .rightMirrored:
        transform = transform.translatedBy(x: 0, y: size.width)
        transform = transform.rotated(by: -CGFloat.pi/2)
        break
    case .up, .upMirrored:
        break
    }

    if [.upMirrored, .downMirrored,.leftMirrored, .rightMirrored].contains(imageOrientation) {
        transform = transform.translatedBy(x: size.width, y: 0)
        transform = transform.scaledBy(x: -1, y: 1)
    }

    ctx.concatenate(transform)
    // Interestingly, drawing with the original width and height?!
    // So width and height here are pre-transform.

    ctx.draw(self, in: CGRect(x: 0, y: 0, width: size.width, height: size.height))

    return (ctx.makeImage(), transform)
}

}

使用：-

var tempImage = imgae
        guard let cgImage = imgae?.cgImage else {return}

        if let orientedImage = cgImage.orientImage(.upMirrored) {
            tempImage = UIImage(cgImage: orientedImage)
        }
        let image = UIImageView(image: tempImage)

Answer 3

问题在于您在将UIImage转换为CGImage时丢弃了图像元数据（包括方向）。 你需要在访问它的cgImage属性之前呈现一个新的UIImage ，正如我在这篇文章中展示的

---

if let data = photo.fileDataRepresentation(), let image = UIImage(data: data) {
    let renderedImage = UIGraphicsImageRenderer(size: size, format: imageRendererFormat).image { _ in image.draw(at: .zero) }
    // use renderedImage image
}

Answer 4

尝试以下功能来修复方向：

extension UIImage {
    func makeFixOrientation() -> UIImage {
        if self.imageOrientation == UIImage.Orientation.up {
            return self
        }

        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
        self.draw(in: CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height))
        let normalizedImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()

        return normalizedImage;
    }
}

Answer 5

从 iOS 4.0 开始，当相机拍照时，在保存之前不会旋转它，它

• 只需在 JPEG 的 EXIF 数据中设置一个旋转标志。如果将 UIImage 保存为 JPEG
• 它将设置旋转标志。PNG 不支持旋转标志。
• 因此，如果您将 UIImage 保存为 PNG，它将被错误地旋转并且没有设置标志来修复它。 因此，如果您想要 PNG 图像，则必须自己旋转它们。

func rotateImage(image: UIImage) -> UIImage? {
            if (image.imageOrientation == UIImage.Orientation.up ) {
                return image
            }
            UIGraphicsBeginImageContext(image.size)
            image.draw(in: CGRect(origin: CGPoint.zero, size: image.size))
            let copy = UIGraphicsGetImageFromCurrentImageContext()
            UIGraphicsEndImageContext()
            return copy
        }

Answer 6

您应该在拍摄照片之前在输出中设置方向。

// set the image orientation in output
  if let photoOutputConnection = self.photoOutput.connection(with: .video) {
        photoOutputConnection.videoOrientation = videoPreviewLayerOrientation!
    }

self.photoOutput.capturePhoto(with: photoSettings, delegate: photoCaptureProcessor) // capture image