修复使用前置摄像头 ios 拍摄的图像的方向

Question

I'm using custom camera implementation in my app using Swift. When the image is captured, is called func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) . I get the image data with photo.fileDataRepresentation() and after that I'm fixing the orientation of the photo using the following extension on UIImage .

func fixedOrientation() -> UIImage? {
    guard imageOrientation != UIImage.Orientation.up else {
        // This is default orientation, don't need to do anything
        return self.copy() as? UIImage
    }
    
    guard let cgImage = self.cgImage else {
        // CGImage is not available
        return nil
    }
    
    guard let colorSpace = cgImage.colorSpace, let ctx = CGContext(data: nil, width: Int(size.width), height: Int(size.height), bitsPerComponent: cgImage.bitsPerComponent, bytesPerRow: 0, space: colorSpace, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue) else {
        return nil // Not able to create CGContext
    }
    
    var transform = CGAffineTransform.identity
    
    switch imageOrientation {
    case .down, .downMirrored:
        transform = transform.translatedBy(x: size.width, y: size.height)
        transform = transform.rotated(by: CGFloat.pi)
    case .left, .leftMirrored:
        transform = transform.translatedBy(x: size.width, y: 0)
        transform = transform.rotated(by: CGFloat.pi / 2.0)
    case .right, .rightMirrored:
        transform = transform.translatedBy(x: 0, y: size.height)
        transform = transform.rotated(by: CGFloat.pi / -2.0)
    case .up, .upMirrored:
        break
    @unknown default:
        break
    }
    
    // Flip image one more time if needed to, this is to prevent flipped image
    switch imageOrientation {
    case .upMirrored, .downMirrored:
        transform = transform.translatedBy(x: size.width, y: 0)
        transform = transform.scaledBy(x: -1, y: 1)
    case .leftMirrored, .rightMirrored:
        transform = transform.translatedBy(x: size.height, y: 0)
        transform = transform.scaledBy(x: -1, y: 1)
    case .up, .down, .left, .right:
        break
    @unknown default:
        break
    }
    
    ctx.concatenate(transform)
    
    switch imageOrientation {
    case .left, .leftMirrored, .right, .rightMirrored:
        ctx.draw(cgImage, in: CGRect(x: 0, y: 0, width: size.height, height: size.width))
    default:
        ctx.draw(cgImage, in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
    }
    
    guard let newCGImage = ctx.makeImage() else { return nil }
    return UIImage(cgImage: newCGImage, scale: 1, orientation: .up)
}

Apparently this is working fine for images taken with back camera, but taking with frontal one I'm facing issues.

1. If the selfie photo is taken in portrait, the the method returns the photo mirrored.(which is not a big deal)
2. If the selfie photo is taken in landscape right/left, the outcode is photo also mirrored but wrongfully rotated. Here is where I want your help, to get the correct rotation of the photo.
   

Note : I'm also changing the videoOrientation from AVCaptureConnection when rotating the device.

Answer 1

It turned out that i was changing the videoOrientation when rotation did change, which was wrong. I had to move that logic before capturing the photo. Now it works fine. Also I've fixed the mirroring problem, by setting isVideoMirrored to true if using the front camera.