UIImagePickerController中的前置摄像头

时间：2012-02-13 04:30:50

标签： ios objective-c iphone swift uiimagepickercontroller

我正在使用UIImagePickerController开发iPad2中的前置摄像头应用程序。

当我捕捉到图像时，它显示为从左向右翻转。

我该如何纠正？

if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) 
    {
        UIImagePickerController *imgPkr = [[UIImagePickerController alloc] init];
        imgPkr.delegate = self;
        imgPkr.sourceType = UIImagePickerControllerSourceTypeCamera;
        imgPkr.cameraDevice=UIImagePickerControllerCameraDeviceFront;


        UIImageView *anImageView=[[UIImageView alloc] initWithImage:[UIImage imageNamed:[NSString stringWithFormat:@"select%d.png",val]]];
        anImageView.frame = CGRectMake(0, 0, anImageView.image.size.width, anImageView.image.size.height);
        imgPkr.cameraOverlayView = anImageView;
        [theApp.TabViewControllerObject presentModalViewController:imgPkr animated:YES];
        [imgPkr release];
    }

9 个答案:

答案 0 :(得分：75)

您可以使用此

翻转源图像中的图像 
UIImage *flippedImage = [UIImage imageWithCGImage:picture.CGImage scale:picture.scale orientation:UIImageOrientationLeftMirrored];

修改：添加了快速代码

let flippedImage = UIImage(CGImage: picture.CGImage, scale: picture.scale, orientation:.LeftMirrored)

答案 1 :(得分：19)

我遇到了同样的问题 - 上面的解决方案只给我一半的答案，因为用户必须先批准镜像后才能进入我的应用程序的下一页 - 我在翻转后使用捕获的图像。 / p>

要解决此问题，每当我切换到前置摄像头时，我都必须翻转摄像机视图：

- (IBAction)flipCamera:(id)sender {
if(cameraUI.cameraDevice == UIImagePickerControllerCameraDeviceFront)
{
    cameraUI.cameraDevice = UIImagePickerControllerCameraDeviceRear;
}
else {
    cameraUI.cameraDevice = UIImagePickerControllerCameraDeviceFront;
}
cameraUI.cameraViewTransform = CGAffineTransformScale(cameraUI.cameraViewTransform, -1,     1);     
}

只是为了扩展这个伟大的答案，一些典型的完整代码，Dec2013，iOS7 / Xcode5。做一切。你只需要一个图标（示例中为cameraToggle.PNG）。

-(void)showTheDeviceCamera
    {
    if ( ! [UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera] )
        return;

    // self.cameraController is a UIImagePickerController
    self.cameraController = [[UIImagePickerController alloc] init];
    self.cameraController.delegate = (id)self;
    self.cameraController.mediaTypes = @[(NSString *)kUTTypeImage];
    self.cameraController.allowsEditing = YES;
    self.cameraController.sourceType = UIImagePickerControllerSourceTypeCamera;
    [self presentViewController:self.cameraController animated:YES completion:NULL];


        // Add front-rear toggle button MANUALLY, IF NECESSARY
        // (You seem to usually get it for free, on iPhone, but
        // need to add manually on an iPad.)

        UIView *buttonView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"cameraToggle"]];
        [buttonView sizeToFit];

        buttonView.userInteractionEnabled = YES;
        [self.cameraController.view addSubview:buttonView];

        UITapGestureRecognizer *tap =
            [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(_frontRearButtonClicked) ];
        tap.numberOfTapsRequired = 1;
        [buttonView addGestureRecognizer:tap];

        // we'll add it at the top right .. could be anywhere you want
        buttonView.center = CGPointMake(
                self.cameraController.view.frame.size.width-buttonView.frame.size.width,
                3.0 * buttonView.frame.size.height
                );

    }

-(void)_frontRearButtonClicked
    {
    [UIView transitionWithView:self.cameraController.view
        duration:1.0
        options:UIViewAnimationOptionAllowAnimatedContent | UIViewAnimationOptionTransitionFlipFromLeft
        animations:^{
            if ( self.cameraController.cameraDevice == UIImagePickerControllerCameraDeviceRear )
                self.cameraController.cameraDevice = UIImagePickerControllerCameraDeviceFront;
            else
                self.cameraController.cameraDevice = UIImagePickerControllerCameraDeviceRear;
        } completion:NULL];
    }

答案 2 :(得分：10)

正如其他答案，我遇到了同样的问题。正如Yonatan Betzer所提到的，只是翻转最终图像只有答案的一半，因为预览图像由UIPickerController在用前置摄像头拍照时显示，它仍然是倒置的（镜像）。

Yonatan Betzer的anwser效果很好，但他没有提到如何或在何处采取行动来改变相机设备。

基于互联网的一些代码，我创建了一个Pod来获得这种想要的行为：

https://github.com/lucasecf/LEMirroredImagePicker

安装完成后，您只需要将这两行代码与UIImagePickerController：

一起调用 
self.mirrorFrontPicker = [[LEMirroredImagePicker alloc] initWithImagePicker:pickerController];
[self.mirrorFrontPicker mirrorFrontCamera];

就是这样，就像那样。您可以在github链接的README中查看更多信息。

答案 3 :(得分：6)

添加UIImagePickerController的子类并且不向摄像机视图添加额外的按钮，只是为了添加我刚刚实现的目的。

只需更改相机更改时多次触发此通知：

[[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(cameraChanged:)
                                                 name:@"AVCaptureDeviceDidStartRunningNotification"
                                               object:nil];

然后使用此方法翻转相机视图：

- (void)cameraChanged:(NSNotification *)notification
{
    if(imagePicker.cameraDevice == UIImagePickerControllerCameraDeviceFront)
    {
        imagePicker.cameraViewTransform = CGAffineTransformIdentity;
        imagePicker.cameraViewTransform = CGAffineTransformScale(imagePicker.cameraViewTransform, -1,     1);
    } else {
        imagePicker.cameraViewTransform = CGAffineTransformIdentity;
    }
}

答案 4 :(得分：6)

我知道这个问题真的很旧但似乎这仍是一个常见的问题。只需在CGAffineTransform对象的cameraViewTransform属性上设置UIImagePickerController即可。 

let picker = UIImagePickerController()
picker.cameraViewTransform = CGAffineTransformScale(picker.cameraViewTransform, -1, 1)

答案 5 :(得分：2)

更新了“ bandog”答案，以实现快速4 

let picker = UIImagePickerController()
picker.cameraViewTransform = picker.cameraViewTransform.scaledBy(x: -1, y: 1)

答案 6 :(得分：2)

我花了几个小时，但我想我到了。这是 Swift 5.2 的有效解决方案，该解决方案说明了如何获取正确的图像（在ImagePicker预览和输出中）。 


     //Registering to get notification when users takes a picture

    override func viewDidLoad() {
        NotificationCenter.default.addObserver(forName: NSNotification.Name(rawValue: "_UIImagePickerControllerUserDidCaptureItem"), object: nil, queue: nil) { (notification) in
            self.changePhotoOrientation()
    }

    //Changing image orientation for ImagePicker preview

    func changePhotoOrientation() {
        var subviews: [UIView] = [imagePicker.view]
        while (!subviews.isEmpty) {
            let subview = subviews.removeFirst()
            subviews += subview.subviews
            if (subview.isKind(of: UIImageView.self)) {
                subview.transform = self.imagePicker.cameraViewTransform.scaledBy(x: -1, y: 1)
            }
        }
    }

    //Changing image orientation for the output image

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        if let userPickedImage = info[UIImagePickerController.InfoKey.originalImage] as? UIImage {
            image = UIImage(cgImage: userPickedImage.cgImage!, scale: userPickedImage.scale, orientation: .leftMirrored)
        }
    }

}

答案 7 :(得分：0)

Swift 中的完整工作示例，它回答了这篇文章的初始问题（使用iOS 8.2在iPhone 5c上测试过）：

        import UIKit

        class ViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate, UIActionSheetDelegate {

         @IBOutlet var myUIImageView: UIImageView!

         var myUIImagePickerController: UIImagePickerController!

         override func viewDidLoad() {
             super.viewDidLoad()
         }

         override func viewWillAppear(animated: Bool) {
             println("viewWillAppear(animated: Bool) method called.")
             super.viewWillAppear(animated)
             NSNotificationCenter.defaultCenter().removeObserver(self)
         }

         override func viewWillDisappear(animated: Bool) {
             println("viewWillDisappear(animated: Bool) method called.")
             super.viewWillDisappear(animated)
             NSNotificationCenter.defaultCenter().addObserver(self, selector: "cameraChanged:", name: "AVCaptureDeviceDidStartRunningNotification", object: nil)
         }

         /* UIImagePickerControllerDelegate Section */
         func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject : AnyObject]) {
              if(self.myUIImagePickerController.sourceType == UIImagePickerControllerSourceType.Camera) {
                 self.myUIImageView.image = info[UIImagePickerControllerEditedImage] as? UIImage
              } else {
                 self.myUIImageView.image = info[UIImagePickerControllerOriginalImage] as? UIImage
              }
              self.dismissViewControllerAnimated(true, completion: nil)
         }

        func imagePickerControllerDidCancel(picker: UIImagePickerController) {
            self.dismissViewControllerAnimated(true, completion: nil)
        }

        /*
        You can choose to use one of the UIResponder methods:
        touchesBegan, touchesMoved, touchesEnded etc, in order to detect the touch
        on the UIImageView.
        */
        override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {
            let touch: UITouch? = touches.anyObject() as? UITouch
            if (touch?.view == myUIImageView) {
                println("myUIImageView has been tapped by the user.")
                self.takingAPictureUsingTheCamera()
            }
        }

        func takingAPictureUsingTheCamera() {
            self.myUIImagePickerController = UIImagePickerController()
            self.myUIImagePickerController.delegate = self // Set the delegate
            self.myUIImagePickerController.sourceType = UIImagePickerControllerSourceType.Camera
            self.myUIImagePickerController.cameraDevice = UIImagePickerControllerCameraDevice.Front
    //        self.myUIImagePickerController.editing = true
            self.myUIImagePickerController.allowsEditing = true
            self.presentViewController(self.myUIImagePickerController, animated: true, completion: nil)
        }

        func cameraChanged(notification: NSNotification) {
             println("cameraChanged(notification: NSNotification) method called.")
             self.myUIImagePickerController.cameraViewTransform = CGAffineTransformIdentity
             if(self.myUIImagePickerController.cameraDevice == UIImagePickerControllerCameraDevice.Front){
                 self.myUIImagePickerController.cameraViewTransform = CGAffineTransformScale(self.myUIImagePickerController.cameraViewTransform, -1, 1)
             }
        }
       }// End class

答案 8 :(得分：0)

看起来AVCaptureDeviceDidStartRunningNotification不再可用作检测相机设备更改的方法。此外，cameraDevice上的UIImagePickerController属性不适用于KVO。但是，仍然可以检测到摄像机设备的更改，如下所示（尽管我们在未明确标记为符合KVO标准的属性上使用KVO，因此无法保证对此解决方案的长期支持。）

import AVFoundation

var context = 0

override func viewDidLoad() {
    super.viewDidLoad()
    // Register for notifications
    let notificationCenter = NSNotificationCenter.defaultCenter()
    notificationCenter.addObserver(self, selector: #selector(handleCaptureSessionDidStartRunning(_:)), name: AVCaptureSessionDidStartRunningNotification, object: nil)
    notificationCenter.addObserver(self, selector: #selector(handleCaptureSessionDidStopRunning(_:)), name: AVCaptureSessionDidStopRunningNotification, object: nil)
}

deinit {
    NSNotificationCenter.defaultCenter().removeObserver(self)
}

func handleCaptureSessionDidStartRunning(notification: NSNotification) {
    guard let session = notification.object as? AVCaptureSession else { return }
    session.addObserver(self, forKeyPath: "inputs", options: [ .Old, .New ], context: &context)
}

func handleCaptureSessionDidStopRunning(notification: NSNotification) {
    guard let session = notification.object as? AVCaptureSession else { return }
    session.removeObserver(self, forKeyPath: "inputs")
}

override func observeValueForKeyPath(keyPath: String?, ofObject object: AnyObject?, change: [String : AnyObject]?, context: UnsafeMutablePointer<Void>) {
    if context == &self.context {
        if let inputs = change?[NSKeyValueChangeNewKey] as? [AnyObject], captureDevice = (inputs.first as? AVCaptureDeviceInput)?.device {
            switch captureDevice.position {
            case .Back: print("Switched to back camera")
            case .Front: print("Switched to front camera")
            case .Unspecified: break
            }
        }
    } else {
        super.observeValueForKeyPath(keyPath, ofObject: object, change: change, context: context)
    }
}
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