Tôi đã viết UICropperViewController
và nó hoạt động hoàn hảo cho hình ảnh ở chế độ ngang. Hình ảnh ở chế độ dọc có một vấn đề lớn. Bức tranh sau đây cho thấy một bức tranh đơn giản với một khung cắt vàng:Tại sao cgImage? .cropping xoay hình ảnh?
Kết quả thu họach:
Bây giờ khi nói đến hình ảnh chân dung chúng tôi đã nhận tình trạng này:
với kết quả sau:
Vậy điều gì sẽ xảy ra ở đây? Hình ảnh gốc được tự động xoay sang trái.
tôi nghiên cứu rất nhiều và về cơ bản tìm thấy hai gợi ý:
Đề xuất 1
Lưu định hướng hình ảnh trước khi cắt xén và khôi phục lại nó.
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);
}
Nhưng kết quả bây giờ là:
Vì vậy, rõ ràng là đề nghị này không hiệu quả vì nó chỉ đơn giản là quay trở lại hình ảnh đã được cắt.
Đề xuất 2
Định hướng sửa chữa. Tôi đã tìm thấy đoạn mã sau đây với lời hứa rằng nó sẽ sửa lỗi:
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
}
}
Nhưng điều này dẫn đến khu vực cắt xén sai. Kết quả bây giờ có thể được cái gì đó như:
Vì vậy, những gì có thể là một giải pháp thực tế cho vấn đề đó? Dù sao, cảm giác xoay hình ảnh tự động như thế nào nếu người dùng không muốn nó? Có thể tắt tính năng xoay tự động này không?
EDIT
Hoàn Nguồn Cropper tôi:
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;
}
}
Nhân tiện, hãy xem http://stackoverflow.com/questions/158914/cropping-an-uiimage/14712184#14712184 để thực hiện rất đơn giản xoay vòng cắt trực tiếp thay vì toàn bộ hình ảnh. Ngoài ra, http://stackoverflow.com/a/18602671/669586 là một giải pháp rất đơn giản. – Sulthan
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