UIImage在裁剪后旋转

Question

我有一个类设置，允许用户从他们的库中添加图像，裁剪并保存它。

设置代码，以便如果检索到的图像是纵向的，则纵向出现纵向边框，以便在裁切之前对齐所有图像，并且如果横向，则出现园景边框。

如果选择的图像是规则形状的图像，则一切正常。但是，如果检索到的图像是纵向而不是正常比例（意思是接近正方形而实际上不是正方形），则图像在裁剪后会旋转。似乎认为该系统将其视为景观图像。

下面是裁剪之前和之后的示例。即使我放大，使图像覆盖整个屏幕，它旋转图像：

import Foundation 
import UIKit 

class SelectImageViewController: UIViewController, UIImagePickerControllerDelegate,UINavigationControllerDelegate,UIScrollViewDelegate{ 


    @IBOutlet weak var imageView: UIImageView! 

    @IBOutlet weak var imageConstraintTop: NSLayoutConstraint! 
    @IBOutlet weak var imageConstraintRight: NSLayoutConstraint! 
    @IBOutlet weak var imageConstraintLeft: NSLayoutConstraint! 
    @IBOutlet weak var imageConstraintBottom: NSLayoutConstraint! 

    var lastZoomScale: CGFloat = -1 
    var imageName: String = "" 
    var userPhotoUUID = UUID().uuidString 
    let userDefault = UserDefaults.standard 
    var userDatabase: UserDatabase = UserDatabase() 
    let picker = UIImagePickerController() 


    @IBOutlet var scrollView: UIScrollView!{ 
     didSet{ 
      scrollView.delegate = self 
      scrollView.minimumZoomScale = 1.0 
      scrollView.maximumZoomScale = 5.0 
     } 
    } 

    @IBOutlet weak var ratioSelector: UISegmentedControl! 

    @IBOutlet var cropAreaViewL: CropAreaViewL! 

    var cropAreaL:CGRect{ 
     get{ 
      let factor = imageView.image!.size.width/view.frame.width 
      let scale = 1/scrollView.zoomScale 
      let imageFrame = imageView.imageFrame() 
      let x = (scrollView.contentOffset.x + cropAreaViewL.frame.origin.x - imageFrame.origin.x) * scale * factor 
      let y = (scrollView.contentOffset.y + cropAreaViewL.frame.origin.y - imageFrame.origin.y) * scale * factor 
      let width = cropAreaViewL.frame.size.width * scale * factor 
      let height = cropAreaViewL.frame.size.height * scale * factor 
      return CGRect(x: x, y: y, width: width, height: height) 
     } 
    } 

    @IBOutlet var cropAreaViewP: CropAreaViewP! 

    var cropAreaP:CGRect{ 
     get{ 
      let factor = imageView.image!.size.height/view.frame.height 
      let scale = 1/scrollView.zoomScale 
      let imageFrame = imageView.imageFrame() 
      let x = (scrollView.contentOffset.x + cropAreaViewP.frame.origin.x - imageFrame.origin.x) * scale * factor 
      let y = (scrollView.contentOffset.y + cropAreaViewP.frame.origin.y - imageFrame.origin.y) * scale * factor 
      let width = cropAreaViewP.frame.size.width * scale * factor 
      let height = cropAreaViewP.frame.size.height * scale * factor 
      return CGRect(x: x, y: y, width: width, height: height) 
     } 
    } 


    fileprivate var speciePhotos: Array<SpeciePhotoModel> = [SpeciePhotoModel]() 


    func randomNumber(range: ClosedRange<Int> = 30000...99998) -> Int { 
     let min = range.lowerBound 
     let max = range.upperBound 
     return Int(arc4random_uniform(UInt32(1 + max - min))) + min 
    } 

    override func viewDidLoad() { 
     super.viewDidLoad() 

     navigationItem.rightBarButtonItem = UIBarButtonItem(title: "+", style: .plain, target: self, action: #selector(SelectImageViewController.add(_:))) 

     let id = randomNumber() 
     userDefault.set(id, forKey: "photoID") 

     self.cropAreaViewP.isHidden = true 
     self.cropAreaViewL.isHidden = true 
     self.cropAreaViewL.layer.borderColor = (UIColor.red).cgColor 
     self.cropAreaViewL.layer.borderWidth = 1.0 
     self.cropAreaViewP.layer.borderColor = (UIColor.red).cgColor 
     self.cropAreaViewP.layer.borderWidth = 1.0 
     self.add.layer.cornerRadius = 6.0 
     self.ratioSelector.layer.cornerRadius = 6.0 
     self.tabBarController?.tabBar.isHidden = true 
     self.add.isHidden = true 
     self.ratioSelector.isHidden = true 

     updateZoom() 

    } 


    func updateConstraints() { 
     if let image = imageView.image { 
      let imageWidth = image.size.width 
      let imageHeight = image.size.height 

      let viewWidth = scrollView.bounds.size.width 
      let viewHeight = scrollView.bounds.size.height 

      // center image if it is smaller than the scroll view 
      var hPadding = (viewWidth - scrollView.zoomScale * imageWidth)/2 
      if hPadding < 0 { hPadding = 0 } 

      var vPadding = (viewHeight - scrollView.zoomScale * imageHeight)/2 
      if vPadding < 0 { vPadding = 0 } 

      imageConstraintLeft.constant = hPadding 
      imageConstraintRight.constant = hPadding 

      imageConstraintTop.constant = vPadding 
      imageConstraintBottom.constant = vPadding 

      view.layoutIfNeeded() 
     } 
    } 

    fileprivate func updateZoom() { 
     if let image = imageView.image { 
      var minZoom = min(scrollView.bounds.size.width/image.size.width, 
           scrollView.bounds.size.height/image.size.height) 

      if minZoom > 1 { minZoom = 1 } 

      scrollView.minimumZoomScale = 0.3 * minZoom 

      // Force scrollViewDidZoom fire if zoom did not change 
      if minZoom == lastZoomScale { minZoom += 0.000001 } 

      scrollView.zoomScale = minZoom 
      lastZoomScale = minZoom 
     } 
    } 


    @IBAction func ratioSelector(_ sender: AnyObject) { 

     switch ratioSelector.selectedSegmentIndex 
     { 
     case 0:// Landscape 

      self.cropAreaViewP.isHidden = true 
      self.cropAreaViewL.isHidden = false 

     case 1: // Portrait 

      self.cropAreaViewL.isHidden = true 
      self.cropAreaViewP.isHidden = false 

     default: 
      break; 
     } 
    } 


    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) { 
     dismiss(animated: true, completion: nil) 
    } 

    @IBOutlet weak var add : UIButton! 


    @IBAction func add(_ sender: UIButton) { 

     imageView.image = nil 

     let picker = UIImagePickerController() 
     picker.delegate = self 
     picker.sourceType = .photoLibrary 
     picker.allowsEditing = false 
     self.present(picker, animated: true, completion: nil) 

     self.ratioSelector.isHidden = false 
     self.add.isHidden = false 

     navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Crop", style: .plain, target: self, action: #selector(SelectImageViewController.crop(_:))) 

    } 

    @IBAction func change(_ sender: UIButton) { 

     imageView.image = nil 

     let picker = UIImagePickerController() 
     picker.delegate = self 
     picker.sourceType = .photoLibrary 
     picker.allowsEditing = false 
     self.present(picker, animated: true, completion: nil) 

     navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Crop", style: .plain, target: self, action: #selector(SelectImageViewController.crop(_:))) 

    } 


    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) { 

     let chosenImage = info[UIImagePickerControllerOriginalImage] as! UIImage 

     if chosenImage.size.height > chosenImage.size.width 
     { 
      self.cropAreaViewL.isHidden = true 
      self.cropAreaViewP.isHidden = false 
      self.ratioSelector.selectedSegmentIndex = 1 
      imageView.image = chosenImage 
     } 
     else 
     { 
      self.cropAreaViewP.isHidden = true 
      self.cropAreaViewL.isHidden = false 
      self.ratioSelector.selectedSegmentIndex = 0 
      imageView.image = chosenImage 
     } 
     self.dismiss(animated: true, completion: nil) 
    } 


    @IBAction func crop(_ sender: UIButton) { 

     if cropAreaViewP.isHidden == true { 
      self.cropAreaViewL.layer.borderColor = (UIColor.clear).cgColor 
      let croppedCGImage = imageView.image?.cgImage?.cropping(to: cropAreaL) 
      let croppedImage = UIImage(cgImage: croppedCGImage!) 
      imageView.image = croppedImage 
      scrollView.zoomScale = 1 
     } else { 
      self.cropAreaViewP.layer.borderColor = (UIColor.clear).cgColor 
      let croppedCGImage = imageView.image?.cgImage?.cropping(to: cropAreaP) 
      let croppedImage = UIImage(cgImage: croppedCGImage!) 
      imageView.image = croppedImage 
      scrollView.zoomScale = 1 
     } 

     navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Next", style: .plain, target: self, action: #selector(SelectImageViewController.saveButtonAction(_:))) 


    } 
} 

extension UIImageView{ 
    func imageFrame()->CGRect{ 
     let imageViewSize = self.frame.size 
     guard let imageSize = self.image?.size else{return CGRect.zero} 
     let imageRatio = imageSize.width/imageSize.height 
     let imageViewRatio = imageViewSize.width/imageViewSize.height 

     if imageRatio < imageViewRatio { // Portrait 
      let scaleFactor = imageViewSize.height/imageSize.height 
      let width = imageSize.width * scaleFactor 
      let topLeftX = (imageViewSize.width - width) * 0.5 
      return CGRect(x: topLeftX, y: 0, width: width, height: imageViewSize.height) 
     }else{ // Landscape 
      let scaleFactor = imageViewSize.width/imageSize.width 
      let height = imageSize.height * scaleFactor 
      let topLeftY = (imageViewSize.height - height) * 0.5 
      return CGRect(x: 0, y: topLeftY, width: imageViewSize.width, height: height) 
     } 
    } 
} 


class CropAreaViewL: UIView { 

    override func point(inside point: CGPoint, with event: UIEvent?) -> Bool { 
     return false 
    } 
} 

class CropAreaViewP: UIView { 

    override func point(inside point: CGPoint, with event: UIEvent?) -> Bool { 
     return false 
    } 

} 

任何帮助将是巨大的。

Answer 1

您可以使用最多的方法，以确保你不会低于零值：

let vPadding = max((viewHeight - scrollView.zoomScale * imageHeight)/2, 0) 

如果你需要让你的形象平方你可以做如下：

extension UIImage { 

    var isPortrait: Bool { return size.height > size.width } 
    var isLandscape: Bool { return size.width > size.height } 
    var breadth:  CGFloat { return min(size.width, size.height) } 
    var breadthSize: CGSize { return CGSize(width: breadth, height: breadth) } 
    var squared: UIImage? { 
     guard let cgImage = cgImage?.cropping(to: 
      CGRect(origin: CGPoint(x: isLandscape ? floor((size.width-size.height)/2) : 0, y: isPortrait ? floor((size.height-size.width)/2) : 0), 
        size: breadthSize)) else { return nil } 
     return UIImage(cgImage: cgImage) 
    } 
} 

要修复方向问题，您需要重新绘制图像，您可以使用此answer的flatten属性。

---

游乐场：

let profilePicture = UIImage(data: try! Data(contentsOf: URL(string:"https://i.stack.imgur.com/Xs4RX.jpg")!))! 
if let squared = profilePicture.squared { 
    squared 

}