拍摄照片时正确设置正确的照片方向
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【中文标题】拍摄照片时正确设置正确的照片方向【英文标题】：Correctly set the right picture orientation when shooting photo 【发布时间】：2022-01-14 11:43:30 【问题描述】：在我用 Swift 编写的 ios 应用上，我需要拍照并将它们保存在图库中；作为Apple文档，如果手机是纵向的，所有照片都是横向拍摄的；如果我们按原样保存图片，它将旋转 90° 保存。
问题：保存图片时如何正确管理设备方向？
感谢一些搜索，我使用了这个解决方案：
func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?)
// ...error handling here
guard let imageData = photo.fileDataRepresentation(with: self) else
NSLog("Fail to convert pixel buffer")
return
// Save image to gallery here
我的班级是AVCapturePhotoFileDataRepresentationCustomizer 代表，所以：
func replacementMetadata(for photo: AVCapturePhoto) -> [String : Any]?
var properties = photo.metadata
// Image orientation
properties[kCGImagePropertyOrientation as String] = CGImagePropertyOrientation.right
let exifData = NSMutableDictionary(dictionary: properties[kCGImagePropertyExifDictionary as String] as! NSDictionary)
let xDimension = exifData[kCGImagePropertyExifPixelYDimension as String]
let yDimension = exifData[kCGImagePropertyExifPixelXDimension as String]
if xDimension != nil && yDimension != nil
exifData[kCGImagePropertyExifPixelXDimension as String] = xDimension
exifData[kCGImagePropertyExifPixelYDimension as String] = yDimension
properties[kCGImagePropertyExifDictionary as String] = exifData
return properties
因为图像是纵向拍摄的，所以方向是 .right，我在搜索中读到 exif 数据中的 X 和 Y 尺寸也应该交换。
不幸的是，一切都没有结果：使用 exif 资源管理器图像方向检查保存的图像仍然是 0=未知值，X 和 Y 仍为原始设置。
我确定数据设置和写入正确，因为：
断点return properties 强调方向标签设置正确；此外，如果标签未正确设置或未知，则应用程序崩溃...
在同一个 replacementMetadata 函数中，我还设置了 GPS 数据（为了简单起见，我在这里剪掉了它！），我写了一些测试值（如标题 = 101），这些数据在最终图像元数据中正确报告。
所以我的问题仍然存在......感谢您使用代码 sn-ps 或文档为我指明正确的方向。
【问题讨论】：
【参考方案1】：您可以通过设置videoOrientation 或AVCapturePhotoOutput 来将拍摄方向设置为您喜欢的任何方向。
为了与当前设备方向匹配，您可以使用UIDevice.current.orientation手动转换为AVCaptureVideoOrientation。
let photoOutput = AVCapturePhotoOutput()
func takeShot()
// set whatever orientation you like
let myShotOrientation = UIDevice.current.orientation.asCaptureVideoOrientation
if let photoOutputConnection = self.photoOutput.connection(with: .video)
photoOutputConnection.videoOrientation = myShotOrientation
photoOutput.capturePhoto(...)
从UIDeviceOrientation 转换为AVCaptureVideoOrientation：
extension UIDeviceOrientation
///
var asCaptureVideoOrientation: AVCaptureVideoOrientation
switch self
// YES, that's not a mistake
case .landscapeLeft: return .landscapeRight
case .landscapeRight: return .landscapeLeft
case .portraitUpsideDown: return .portraitUpsideDown
default: return .portrait
【讨论】：
【参考方案2】：import Foundation
import CoreMotion
import AVFoundation
import UIKit
protocol OrientationHandlerDelegate: class
func didChange(deviceOrientation: UIDeviceOrientation)
class OrientationHandler
private let motionManager = CMMotionManager()
private let queue = OperationQueue()
private var deviceOrientation: UIDeviceOrientation = .unknown
weak var delegate: OrientationHandlerDelegate?
init()
motionManager.accelerometerUpdateInterval = 1.0
motionManager.deviceMotionUpdateInterval = 1.0
motionManager.gyroUpdateInterval = 1.0
motionManager.magnetometerUpdateInterval = 1.0
func startMeasuring()
guard motionManager.isDeviceMotionAvailable else
return
motionManager.startAccelerometerUpdates(to: queue) [weak self] (accelerometerData, error) in
guard let strongSelf = self else
return
guard let accelerometerData = accelerometerData else
return
let acceleration = accelerometerData.acceleration
let xx = -acceleration.x
let yy = acceleration.y
let z = acceleration.z
let angle = atan2(yy, xx)
var deviceOrientation = strongSelf.deviceOrientation
let absoluteZ = fabs(z)
if deviceOrientation == .faceUp || deviceOrientation == .faceDown
if absoluteZ < 0.845
if angle < -2.6
deviceOrientation = .landscapeRight
else if angle > -2.05 && angle < -1.1
deviceOrientation = .portrait
else if angle > -0.48 && angle < 0.48
deviceOrientation = .landscapeLeft
else if angle > 1.08 && angle < 2.08
deviceOrientation = .portraitUpsideDown
else if z < 0
deviceOrientation = .faceUp
else if z > 0
deviceOrientation = .faceDown
else
if z > 0.875
deviceOrientation = .faceDown
else if z < -0.875
deviceOrientation = .faceUp
else
switch deviceOrientation
case .landscapeLeft:
if angle < -1.07
deviceOrientation = .portrait
if angle > 1.08
deviceOrientation = .portraitUpsideDown
case .landscapeRight:
if angle < 0 && angle > -2.05
deviceOrientation = .portrait
if angle > 0 && angle < 2.05
deviceOrientation = .portraitUpsideDown
case .portraitUpsideDown:
if angle > 2.66
deviceOrientation = .landscapeRight
if angle < 0.48
deviceOrientation = .landscapeLeft
case .portrait:
if angle > -0.47
deviceOrientation = .landscapeLeft
if angle < -2.64
deviceOrientation = .landscapeRight
default:
if angle > -0.47
deviceOrientation = .landscapeLeft
if angle < -2.64
deviceOrientation = .landscapeRight
if strongSelf.deviceOrientation != deviceOrientation
strongSelf.deviceOrientation = deviceOrientation
strongSelf.delegate?.didChange(deviceOrientation: deviceOrientation)
func stopMeasuring()
motionManager.stopAccelerometerUpdates()
func currentInterfaceOrientation() -> AVCaptureVideoOrientation
switch deviceOrientation
case .portrait:
return .portrait
case .landscapeRight:
return .landscapeLeft
case .landscapeLeft:
return .landscapeRight
case .portraitUpsideDown:
return .portraitUpsideDown
default:
return .portrait
在您的文件中包含相机代码：
let orientationHandler = OrientationHandler()
当相机处于活动状态时开始测量方向。
orientationHandler.delegate = self
orientationHandler.startMeasuring()
不使用相机时停止测量方向。
orientationHandler.stopMeasuring()
orientationHandler.delegate = nil
最后在调用 capturePhoto 之前添加一行(with: settings, delegate: self)
//Need to correct image orientation before moving further
if let photoOutputConnection = photoOutput?.connection(with: .video)
photoOutputConnection.videoOrientation = orientationHandler.currentInterfaceOrientation()
photoOutput?.capturePhoto(with: settings, delegate: self)
【讨论】：
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