I have written a UICropperViewController and it is working perfectly for images in landscape mode. Images in portrait mode have a huge problem. The following picture shows a simple picture with a yellow crop frame:
我编写了一个UICropperViewController，它非常适合横向模式下的图像。纵向模式下的图像存在很大问题。下图显示了带有黄色裁剪框的简单图片：
The cropping result is:
裁剪结果是：
Now when it comes to portrait images we got this situation:
现在谈到肖像图像我们得到了这种情况：
with the following result:
结果如下：
So what happend here? The original image got automatically rotated to the left.
那么这里发生了什么？原始图像自动旋转到左侧。
I researched alot and basically found two suggestions:
我研究了很多，基本上找到了两个建议：
Suggestion 1
建议1
Save the image orientation before cropping and restore it.
在裁剪之前保存图像方向并恢复它。
func didTapCropButton(sender: AnyObject) {
let originalOrientation = self.imageView.image?.imageOrientation;
// raw value of originalOrientation is `3` so its rotated to the right
let croppedCGImage = self.imageView.image?.cgImage?.cropping(to: self.cropArea);
// create a cropped cgImage
let croppedImage = UIImage(cgImage: croppedCGImage!, scale: (self.imageView.image?.scale)!, orientation: (originalOrientation)!);
// create the UIImage with the result from cgImage cropping and original orientation
if (self.callback != nil) {
self.callback.croppingDone(image: croppedImage);
}
self.dismiss(animated: true, completion: nil);
}
But the result now is:
但结果现在是：
So obviously this suggestion does not work because it is simply rotating back the already cropped image.
显然这个建议不起作用，因为它只是简单地旋转已经裁剪的图像。
Suggestion 2
建议2
Orientation fixing. I found the following piece of code with the promise that it would fix the error:
定位修复。我找到了以下代码，并承诺会修复错误：
func didTapCropButton(sender: AnyObject) {
let image = self.imageView.image?.fixOrientation();
let croppedCGImage = image?.cgImage?.cropping(to: self.cropArea);
let croppedImage = UIImage(cgImage: croppedCGImage!);
if (self.callback != nil) {
self.callback.croppingDone(image: croppedImage);
}
self.dismiss(animated: true, completion: nil);
}
extension UIImage {
/// Extension to fix orientation of an UIImage without EXIF
func fixOrientation() -> UIImage {
guard let cgImage = cgImage else { return self }
if imageOrientation == .up { return self }
var transform = CGAffineTransform.identity
switch imageOrientation {
case .down, .downMirrored:
transform = transform.translatedBy(x: size.width, y: size.height)
transform = transform.rotated(by: CGFloat(M_PI))
case .left, .leftMirrored:
transform = transform.translatedBy(x: size.width, y: 0)
transform = transform.rotated(by: CGFloat(M_PI_2))
case .right, .rightMirrored:
transform = transform.translatedBy(x: 0, y: size.height)
transform = transform.rotated(by: CGFloat(-M_PI_2))
case .up, .upMirrored:
break
}
switch imageOrientation {
case .upMirrored, .downMirrored:
transform.translatedBy(x: size.width, y: 0)
transform.scaledBy(x: -1, y: 1)
case .leftMirrored, .rightMirrored:
transform.translatedBy(x: size.height, y: 0)
transform.scaledBy(x: -1, y: 1)
case .up, .down, .left, .right:
break
}
if let ctx = CGContext(data: nil, width: Int(size.width), height: Int(size.height), bitsPerComponent: cgImage.bitsPerComponent, bytesPerRow: 0, space: cgImage.colorSpace!, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue) {
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))
}
if let finalImage = ctx.makeImage() {
return (UIImage(cgImage: finalImage))
}
}
// something failed -- return original
return self
}
}
But this results in a wrong cropping area. The result now could be something like:
但这会导致错误的裁剪区域。结果现在可能是这样的：
So what could be a real solution for that problem? Anyway, what's the sense of rotating the image automatically if the user does not want it? Is it possible to disable this automatic rotation?
那么这个问题的真正解决方案是什么呢？无论如何，如果用户不想要它，会自动旋转图像的感觉是什么？是否可以禁用此自动旋转？
EDIT
编辑
Complete Source of my Cropper:
我的剪草机的完整来源：
import Foundation
import UIKit
protocol CropperCallback {
func croppingDone(image: UIImage);
func croppingCancelled();
}
class CropperViewController : UIViewController {
@IBOutlet var imageView: UIImageView!;
var imageViewScaleCurrent: CGFloat! = 1.0;
var imageViewScaleMin: CGFloat! = 0.5;
var imageViewScaleMax: CGFloat! = 5.0;
@IBOutlet var cropAreaView: CropAreaView!;
@IBOutlet weak var cropAreaViewConstraintWidth: NSLayoutConstraint!
@IBOutlet weak var cropAreaViewConstraintHeight: NSLayoutConstraint!
@IBOutlet var btnCrop: UIButton!;
@IBOutlet var btnCancel: UIButton!;
var callback: CropperCallback! = nil;
var image: UIImage! = nil;
var imageOriginalWidth: CGFloat!;
var imageOriginalHeight: CGFloat!;
var cropWidth: CGFloat! = 287;/
var cropHeight: CGFloat! = 292;
var cropHeightFix: CGFloat! = 1.0;
var cropArea: CGRect {
get {
let factor = self.imageView.image!.size.width / self.view.frame.width;
let scale = 1 / self.imageViewScaleCurrent;
let x = (self.cropAreaView.frame.origin.x - self.imageView.frame.origin.x) * scale * factor;
let y = (self.cropAreaView.frame.origin.y - self.imageView.frame.origin.y) * scale * factor;
let width = self.cropAreaView.frame.size.width * scale * factor;
let height = self.cropAreaView.frame.size.height * scale * factor;
return CGRect(x: x, y: y, width: width, height: height);
}
}
static func storyboardInstance() -> CropperViewController? {
let storyboard = UIStoryboard(name: String(describing: NSStringFromClass(CropperViewController.classForCoder()).components(separatedBy: ".").last!), bundle: nil);
return storyboard.instantiateInitialViewController() as? CropperViewController;
}
override func viewDidLoad() {
super.viewDidLoad();
/*
if (self.image.imageOrientation != .up) {
self.image = UIImage(cgImage: self.image.cgImage!, scale: self.image.scale, orientation: UIImageOrientation(rawValue: 0)!);
}
*/
self.imageView.image = self.image;
self.imageView.isUserInteractionEnabled = true;
self.imageView.addGestureRecognizer(UIPanGestureRecognizer(target: self, action: #selector(self.handlePan(_:))));
self.imageView.addGestureRecognizer(UIPinchGestureRecognizer(target: self, action: #selector(self.handlePinch(_:))));
self.cropAreaViewConstraintWidth.constant = self.cropWidth;
self.cropAreaViewConstraintHeight.constant = self.cropHeight;
self.btnCrop.addTarget(self, action: #selector(self.didTapCropButton), for: UIControlEvents.touchUpInside);
self.btnCancel.addTarget(self, action: #selector(self.didTapCancelButton), for: UIControlEvents.touchUpInside);
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews();
let imageOriginalRect = self.getRectOfImageInImageView(imageView: self.imageView);
self.imageOriginalWidth = imageOriginalRect.size.width;
self.imageOriginalHeight = imageOriginalRect.size.height;
self.createOverlay();
}
func createOverlay() {
let path = UIBezierPath(rect: CGRect(x: 0, y: 0, width: self.view.frame.size.width, height: self.view.frame.size.height));
let pathRect = UIBezierPath(rect: CGRect(x: self.cropAreaView.frame.origin.x, y: self.cropAreaView.frame.origin.y, width: self.cropWidth, height: self.cropHeight));
path.append(pathRect);
path.usesEvenOddFillRule = true;
let fillLayer = CAShapeLayer();
fillLayer.path = path.cgPath;
fillLayer.fillRule = kCAFillRuleEvenOdd;
fillLayer.fillColor = UIColor.white.cgColor;
fillLayer.opacity = 0.1;
self.view.layer.addSublayer(fillLayer);
}
func handlePan(_ gestureRecognizer: UIPanGestureRecognizer) {
if gestureRecognizer.state == .began || gestureRecognizer.state == .changed {
let rect = self.getRectOfImageInImageView(imageView: self.imageView);
let xImage = rect.origin.x;
let yImage = rect.origin.y;
let widthImage = rect.size.width;
let heightImage = rect.size.height;
let xCropView = self.cropAreaView.frame.origin.x;
let yCropView = self.cropAreaView.frame.origin.y;
let widthCropView = self.cropAreaView.frame.size.width;
let heightCropView = self.cropAreaView.frame.size.height;
let translation = gestureRecognizer.translation(in: self.view);
var x: CGFloat;
var y: CGFloat;
if (translation.x > 0) {
if (!(xImage >= xCropView)) {
x = gestureRecognizer.view!.center.x + translation.x;
} else {
x = gestureRecognizer.view!.center.x;
}
} else if (translation.x < 0) {
if (!((xImage + widthImage) <= (xCropView + widthCropView))) {
x = gestureRecognizer.view!.center.x + translation.x;
} else {
x = gestureRecognizer.view!.center.x;
}
} else {
x = gestureRecognizer.view!.center.x;
}
if (translation.y > 0) {
if (!(yImage >= (yCropView - self.cropHeightFix))) {
y = gestureRecognizer.view!.center.y + translation.y;
} else {
y = gestureRecognizer.view!.center.y;
}
} else if (translation.y < 0) {
if (!((yImage + heightImage) <= (yCropView + heightCropView + self.cropHeightFix))) {
y = gestureRecognizer.view!.center.y + translation.y;
} else {
y = gestureRecognizer.view!.center.y;
}
} else {
y = gestureRecognizer.view!.center.y;
}
gestureRecognizer.view!.center = CGPoint(x: x, y: y);
gestureRecognizer.setTranslation(CGPoint.zero, in: self.view);
self.fixImageViewPosition();
}
}
func handlePinch(_ gestureRecognizer: UIPinchGestureRecognizer) {
if let view = gestureRecognizer.view {
let widthCropView = self.cropAreaView.frame.size.width;
let heightCropView = self.cropAreaView.frame.size.height;
if (((self.imageViewScaleCurrent * gestureRecognizer.scale * self.imageOriginalWidth) > widthCropView)
&& ((self.imageViewScaleCurrent * gestureRecognizer.scale * self.imageOriginalHeight) > (heightCropView + (2 * self.cropHeightFix)))
&& ((self.imageViewScaleCurrent * gestureRecognizer.scale) < self.imageViewScaleMax)) {
self.imageViewScaleCurrent = self.imageViewScaleCurrent * gestureRecognizer.scale;
view.transform = CGAffineTransform(scaleX: self.imageViewScaleCurrent, y: self.imageViewScaleCurrent);
}
gestureRecognizer.scale = 1.0;
self.fixImageViewPosition();
}
}
func fixImageViewPosition() {
let rect = self.getRectOfImageInImageView(imageView: self.imageView);
let xImage = rect.origin.x;
let yImage = rect.origin.y;
let widthImage = rect.size.width;
let heightImage = rect.size.height;
let xCropView = self.cropAreaView.frame.origin.x;
let yCropView = self.cropAreaView.frame.origin.y;
let widthCropView = self.cropAreaView.frame.size.width;
let heightCropView = self.cropAreaView.frame.size.height;
if (xImage > xCropView) {
self.imageView.frame = CGRect(x: xCropView, y: self.imageView.frame.origin.y, width: widthImage, height: heightImage);
}
if ((xImage + widthImage) < (xCropView + widthCropView)) {
self.imageView.frame = CGRect(x: ((xCropView + widthCropView) - widthImage), y: self.imageView.frame.origin.y, width: widthImage, height: heightImage);
}
if (yImage > yCropView) {
self.imageView.frame = CGRect(x: self.imageView.frame.origin.x, y: (yCropView - self.cropHeightFix), width: widthImage, height: heightImage);
}
if ((yImage + heightImage) < (yCropView + heightCropView + self.cropHeightFix)) {
self.imageView.frame = CGRect(x: self.imageView.frame.origin.x, y: ((yCropView + heightCropView + self.cropHeightFix) - heightImage), width: widthImage, height: heightImage);
}
}
func getRectOfImageInImageView(imageView: UIImageView) -> CGRect {
let imageViewSize = imageView.frame.size;
let imageSize = imageView.image!.size;
let scaleW = imageViewSize.width / imageSize.width;
let scaleH = imageViewSize.height / imageSize.height;
let aspect = min(scaleW, scaleH);
var imageRect = CGRect(x: 0, y: 0, width: (imageSize.width * aspect), height: (imageSize.height * aspect));
imageRect.origin.x = (imageViewSize.width - imageRect.size.width) / 2;
imageRect.origin.y = (imageViewSize.height - imageRect.size.height) / 2;
imageRect.origin.x += imageView.frame.origin.x;
imageRect.origin.y += imageView.frame.origin.y;
return imageRect;
}
func getCGImageWithCorrectOrientation(_ image : UIImage) -> CGImage {
if (image.imageOrientation == UIImageOrientation.up) {
return image.cgImage!;
}
var transform : CGAffineTransform = CGAffineTransform.identity;
switch (image.imageOrientation) {
case UIImageOrientation.right, UIImageOrientation.rightMirrored:
transform = transform.translatedBy(x: 0, y: image.size.height);
transform = transform.rotated(by: CGFloat(-1.0 * M_PI_2));
break;
case UIImageOrientation.left, UIImageOrientation.leftMirrored:
transform = transform.translatedBy(x: image.size.width, y: 0);
transform = transform.rotated(by: CGFloat(M_PI_2));
break;
case UIImageOrientation.down, UIImageOrientation.downMirrored:
transform = transform.translatedBy(x: image.size.width, y: image.size.height);
transform = transform.rotated(by: CGFloat(M_PI));
break;
default:
break;
}
switch (image.imageOrientation) {
case UIImageOrientation.rightMirrored, UIImageOrientation.leftMirrored:
transform = transform.translatedBy(x: image.size.height, y: 0);
transform = transform.scaledBy(x: -1, y: 1);
break;
case UIImageOrientation.downMirrored, UIImageOrientation.upMirrored:
transform = transform.translatedBy(x: image.size.width, y: 0);
transform = transform.scaledBy(x: -1, y: 1);
break;
default:
break;
}
let contextWidth : Int;
let contextHeight : Int;
switch (image.imageOrientation) {
case UIImageOrientation.left, UIImageOrientation.leftMirrored,
UIImageOrientation.right, UIImageOrientation.rightMirrored:
contextWidth = (image.cgImage?.height)!;
contextHeight = (image.cgImage?.width)!;
break;
default:
contextWidth = (image.cgImage?.width)!;
contextHeight = (image.cgImage?.height)!;
break;
}
let context : CGContext = CGContext(data: nil, width: contextWidth, height: contextHeight,
bitsPerComponent: image.cgImage!.bitsPerComponent,
bytesPerRow: image.cgImage!.bytesPerRow,
space: image.cgImage!.colorSpace!,
bitmapInfo: image.cgImage!.bitmapInfo.rawValue)!;
context.concatenate(transform);
context.draw(image.cgImage!, in: CGRect(x: 0, y: 0, width: CGFloat(contextWidth), height: CGFloat(contextHeight)));
let cgImage = context.makeImage();
return cgImage!;
}
func didTapCropButton(sender: AnyObject) {
let fixedImage = self.getCGImageWithCorrectOrientation(self.imageView.image!);
// let image = self.imageView.image?.fixOrientation();
let croppedCGImage = fixedImage.cropping(to: self.cropArea);
let croppedImage = UIImage(cgImage: croppedCGImage!);
if (self.callback != nil) {
self.callback.croppingDone(image: croppedImage);
}
self.dismiss(animated: true, completion: nil);
}
func didTapCancelButton(sender: AnyObject) {
if (self.callback != nil) {
self.callback.croppingCancelled();
}
self.dismiss(animated: true, completion: nil);
}
}
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) {
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 {
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);
}
}
}
extension UIImage {
// Extension to fix orientation of an UIImage without EXIF
func fixOrientation() -> UIImage {
guard let cgImage = self.cgImage else {
return self;
}
if self.imageOrientation == .up {
return self;
}
var transform = CGAffineTransform.identity;
switch self.imageOrientation {
case .down, .downMirrored:
transform = transform.translatedBy(x: self.size.width, y: self.size.height);
transform = transform.rotated(by: CGFloat(M_PI));
case .left, .leftMirrored:
transform = transform.translatedBy(x: self.size.width, y: 0);
transform = transform.rotated(by: CGFloat(M_PI_2));
case .right, .rightMirrored:
transform = transform.translatedBy(x: 0, y: self.size.height);
transform = transform.rotated(by: CGFloat(-M_PI_2));
case .up, .upMirrored:
break;
}
switch self.imageOrientation {
case .upMirrored, .downMirrored:
transform.translatedBy(x: self.size.width, y: 0);
transform.scaledBy(x: -1, y: 1);
case .leftMirrored, .rightMirrored:
transform.translatedBy(x: self.size.height, y: 0);
transform.scaledBy(x: -1, y: 1);
case .up, .down, .left, .right:
break;
}
if let ctx = CGContext(data: nil, width: Int(self.size.width), height: Int(self.size.height), bitsPerComponent: cgImage.bitsPerComponent, bytesPerRow: 0, space: cgImage.colorSpace!, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue) {
ctx.concatenate(transform);
switch self.imageOrientation {
case .left, .leftMirrored, .right, .rightMirrored:
ctx.draw(cgImage, in: CGRect(x: 0, y: 0, width: self.size.height, height: self.size.width));
default:
ctx.draw(cgImage, in: CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height));
}
if let finalImage = ctx.makeImage() {
return (UIImage(cgImage: finalImage));
}
}
// something failed -- return original
return self;
}
}
1 个解决方案
#1
6
You have to understand the scale and orientation properties.
您必须了解比例和方向属性。
Your suggestion 1 (use the orientation of the original image) is obviously a correct suggestion and it would work, if you were able to also rotate and scale your cropArea.
您的建议1（使用原始图像的方向）显然是一个正确的建议，如果您还能够旋转和缩放cropArea，它将起作用。
Your suggestion 2 is a good to handle rotation but you still have to scale the cropArea. Currently you are not handling the scale at all.
您的建议2很适合处理轮换，但您仍需要缩放cropArea。目前你根本没有处理规模。
(minor note, rotating cropArea would probably have better performance than rotating the whole image, see https://*.com/a/14712184/669586).
（小调，旋转cropArea可能比旋转整个图像有更好的性能，请参阅https://*.com/a/14712184/669586）。
You have to:
你必须：
- Scale (multiply)
cropAreaby the scale of the image. - 缩放（乘）cropArea按图像的比例。
- Use the original image scale when creating the result
- 创建结果时使用原始图像比例
For example, if your UIImage has size 200x100 and it has scale 2x (it's a retina image), your cgImage will have size 400x200 but you are still working with a crop area inside 200x100!
例如，如果您的UIImage尺寸为200x100且尺寸为2x（它是视网膜图像），则cgImage的尺寸为400x200，但您仍在使用200x100内的裁剪区域！
Something along the lines of:
有点像：
func didTapCropButton(sender: AnyObject) {
guard let image = self.imageView.image else {
return
}
let cgImage = self.getCGImageWithCorrectOrientation(image);
let scaledCropArea = CGRect(
x: self.cropArea.x * image.scale,
y: self.cropArea.y * image.scale,
width: self.cropArea.width * image.scale,
height: self.cropArea.height * image.scale
)
let croppedCGImage = cgImage.cropping(to: scaledCropArea)
let croppedImage = UIImage(cgImage: croppedCGImage!, scale: image.scale, orientation: .up)
if (self.callback != nil) {
self.callback.croppingDone(image: croppedImage)
}
self.dismiss(animated: true, completion: nil)
}
The automatic rotation and transforms in UIImage are simply an optimization. Thanks to this optimization, multiple images can share the same storage (the same memory data). The optimization is done already in your asset loader and you cannot disable it.
UIImage中的自动旋转和变换只是一种优化。由于这种优化，多个图像可以共享相同的存储（相同的存储器数据）。优化已在资产加载器中完成，您无法禁用它。
Also, please see https://*.com/a/18602671/669586 for a simpler and safer implementation.
另外，请参阅https://*.com/a/18602671/669586以获得更简单，更安全的实现。
#1
6
You have to understand the scale and orientation properties.
您必须了解比例和方向属性。
Your suggestion 1 (use the orientation of the original image) is obviously a correct suggestion and it would work, if you were able to also rotate and scale your cropArea.
您的建议1（使用原始图像的方向）显然是一个正确的建议，如果您还能够旋转和缩放cropArea，它将起作用。
Your suggestion 2 is a good to handle rotation but you still have to scale the cropArea. Currently you are not handling the scale at all.
您的建议2很适合处理轮换，但您仍需要缩放cropArea。目前你根本没有处理规模。
(minor note, rotating cropArea would probably have better performance than rotating the whole image, see https://*.com/a/14712184/669586).
（小调，旋转cropArea可能比旋转整个图像有更好的性能，请参阅https://*.com/a/14712184/669586）。
You have to:
你必须：
- Scale (multiply)
cropAreaby the scale of the image. - 缩放（乘）cropArea按图像的比例。
- Use the original image scale when creating the result
- 创建结果时使用原始图像比例
For example, if your UIImage has size 200x100 and it has scale 2x (it's a retina image), your cgImage will have size 400x200 but you are still working with a crop area inside 200x100!
例如，如果您的UIImage尺寸为200x100且尺寸为2x（它是视网膜图像），则cgImage的尺寸为400x200，但您仍在使用200x100内的裁剪区域！
Something along the lines of:
有点像：
func didTapCropButton(sender: AnyObject) {
guard let image = self.imageView.image else {
return
}
let cgImage = self.getCGImageWithCorrectOrientation(image);
let scaledCropArea = CGRect(
x: self.cropArea.x * image.scale,
y: self.cropArea.y * image.scale,
width: self.cropArea.width * image.scale,
height: self.cropArea.height * image.scale
)
let croppedCGImage = cgImage.cropping(to: scaledCropArea)
let croppedImage = UIImage(cgImage: croppedCGImage!, scale: image.scale, orientation: .up)
if (self.callback != nil) {
self.callback.croppingDone(image: croppedImage)
}
self.dismiss(animated: true, completion: nil)
}
The automatic rotation and transforms in UIImage are simply an optimization. Thanks to this optimization, multiple images can share the same storage (the same memory data). The optimization is done already in your asset loader and you cannot disable it.
UIImage中的自动旋转和变换只是一种优化。由于这种优化，多个图像可以共享相同的存储（相同的存储器数据）。优化已在资产加载器中完成，您无法禁用它。
Also, please see https://*.com/a/18602671/669586 for a simpler and safer implementation.
另外，请参阅https://*.com/a/18602671/669586以获得更简单，更安全的实现。