iPhone AVFoundation camera orientation

Question

I\'ve been tearing my hair out trying to get the AVFoundation camera to capture a picture in the correct orientation (i.e. the device orientation) but I can\'t get it to wor

Answer 1

I am writing this code in Swift in case may be needful for someone.

Step-1: Generate Orientation notifications (in yourviewDidLoad)

    UIDevice.currentDevice().beginGeneratingDeviceOrientationNotifications()
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("deviceOrientationDidChange:"), name: UIDeviceOrientationDidChangeNotification, object: nil)

Step-2: Take picture. Here we will interchange orientation of videoConnection. In AVFoundation there is a minor change in orientation especially for landscape orientation. So we will just interchange it. For example we will change from LandscapeRight to LandscapeLeft and viceversa

  func takePicture() {
if let videoConnection = stillImageOutput!.connectionWithMediaType(AVMediaTypeVideo) {

    var newOrientation: AVCaptureVideoOrientation?
    switch (UIDevice.currentDevice().orientation) {
    case .Portrait:
        newOrientation = .Portrait
        break
    case .PortraitUpsideDown:
        newOrientation = .PortraitUpsideDown
        break
    case .LandscapeLeft:
        newOrientation = .LandscapeRight
        break
    case .LandscapeRight:
        newOrientation = .LandscapeLeft
        break
    default :
        newOrientation = .Portrait
        break

    }
    videoConnection.videoOrientation = newOrientation!


  stillImageOutput!.captureStillImageAsynchronouslyFromConnection(videoConnection) {
    (imageDataSampleBuffer, error) -> Void in

    let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(imageDataSampleBuffer)

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0)) {

      dispatch_async(dispatch_get_main_queue()) {

        let image = UIImage(data: imageData!)!
        let portraitImage = image.fixOrientation()


      }
    }


  }
}

  }

NOTE: Please notice the new orientation value for Landscape orientations. Its just the opposite. (This is the culprit ::UHHHH)

Step-3: Fix orientation (UIImage extension)

extension UIImage {

func fixOrientation() -> UIImage {

    if imageOrientation == UIImageOrientation.Up {
        return self
    }

    var transform: CGAffineTransform = CGAffineTransformIdentity

    switch imageOrientation {
    case UIImageOrientation.Down, UIImageOrientation.DownMirrored:
        transform = CGAffineTransformTranslate(transform, size.width, size.height)
        transform = CGAffineTransformRotate(transform, CGFloat(M_PI))
        break
    case UIImageOrientation.Left, UIImageOrientation.LeftMirrored:
        transform = CGAffineTransformTranslate(transform, size.width, 0)
        transform = CGAffineTransformRotate(transform, CGFloat(M_PI_2))
        break
    case UIImageOrientation.Right, UIImageOrientation.RightMirrored:
        transform = CGAffineTransformTranslate(transform, 0, size.height)
        transform = CGAffineTransformRotate(transform, CGFloat(-M_PI_2))
        break
    case UIImageOrientation.Up, UIImageOrientation.UpMirrored:
        break
    }

    switch imageOrientation {
    case UIImageOrientation.UpMirrored, UIImageOrientation.DownMirrored:
        CGAffineTransformTranslate(transform, size.width, 0)
        CGAffineTransformScale(transform, -1, 1)
        break
    case UIImageOrientation.LeftMirrored, UIImageOrientation.RightMirrored:
        CGAffineTransformTranslate(transform, size.height, 0)
        CGAffineTransformScale(transform, -1, 1)
    case UIImageOrientation.Up, UIImageOrientation.Down, UIImageOrientation.Left, UIImageOrientation.Right:
        break
    }

    let ctx: CGContextRef = CGBitmapContextCreate(nil, Int(size.width), Int(size.height), CGImageGetBitsPerComponent(CGImage), 0, CGImageGetColorSpace(CGImage), CGImageAlphaInfo.PremultipliedLast.rawValue)!

    CGContextConcatCTM(ctx, transform)

    switch imageOrientation {
    case UIImageOrientation.Left, UIImageOrientation.LeftMirrored, UIImageOrientation.Right, UIImageOrientation.RightMirrored:
        CGContextDrawImage(ctx, CGRectMake(0, 0, size.height, size.width), CGImage)
        break
    default:
        CGContextDrawImage(ctx, CGRectMake(0, 0, size.width, size.height), CGImage)
        break
    }

    let cgImage: CGImageRef = CGBitmapContextCreateImage(ctx)!

    return UIImage(CGImage: cgImage)
}


   }