iOS UIImagePickerController上传后的结果图像方向

我正在iOS 3.1.3 iPhone上测试我的iPhone应用程序。我正在使用UIImagePickerController选择/捕获图像:

UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
[imagePicker setSourceType:UIImagePickerControllerSourceTypeCamera];
[imagePicker setDelegate:self];
[self.navigationController presentModalViewController:imagePicker animated:YES];
[imagePicker release];






- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
self.image = [info objectForKey:UIImagePickerControllerOriginalImage];
imageView.image = self.image;
[self.navigationController dismissModalViewControllerAnimated:YES];
submitButton.enabled = YES;
}

然后在某个时候，我使用ASI类将它发送到我的web服务器:

ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:[NSURL URLWithString:@"http://example.com/myscript.php"]];
[request setDelegate:self];
[request setStringEncoding:NSUTF8StringEncoding];
[request setShouldContinueWhenAppEntersBackground:YES];
//other post keys/values
[request setFile:UIImageJPEGRepresentation(self.image, 100.0f) withFileName:[NSString stringWithFormat:@"%d.jpg", [[NSDate date] timeIntervalSinceNow]] andContentType:@"image/jpg" forKey:@"imageFile"];
[request startAsynchronous];
< p >问题: 当我拿着iPhone拍照时，照片会被上传到服务器，就像你期望的那样。手持手机竖屏拍照时，上传和观看的图像是旋转90度

我的应用程序被设置为只在纵向模式(倒置和常规)下工作。

我怎样才能使图像始终显示正确的方向后上传?

在UIImageView中显示的图像是正确的(直接在拍照后)，但在服务器上查看则不然。

143649 次浏览
小开
最佳答案

UIImage有一个属性imageOrientation，它指示UIImageView和其他UIImage消费者旋转原始图像数据。在上传的jpeg图像中，这个标志很有可能被保存到exif数据中，但是用于查看它的程序没有执行该标志。

为了在上传时旋转UIImage以正确显示，你可以使用这样的类别:

用户界面图像+ fixOrientation.h

@interface UIImage (fixOrientation)


- (UIImage *)fixOrientation;


@end

用户界面图像+ fixOrientation.m

@implementation UIImage (fixOrientation)


- (UIImage *)fixOrientation {


// No-op if the orientation is already correct
if (self.imageOrientation == UIImageOrientationUp) return self;


// We need to calculate the proper transformation to make the image upright.
// We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
CGAffineTransform transform = CGAffineTransformIdentity;


switch (self.imageOrientation) {
case UIImageOrientationDown:
case UIImageOrientationDownMirrored:
transform = CGAffineTransformTranslate(transform, self.size.width, self.size.height);
transform = CGAffineTransformRotate(transform, M_PI);
break;


case UIImageOrientationLeft:
case UIImageOrientationLeftMirrored:
transform = CGAffineTransformTranslate(transform, self.size.width, 0);
transform = CGAffineTransformRotate(transform, M_PI_2);
break;


case UIImageOrientationRight:
case UIImageOrientationRightMirrored:
transform = CGAffineTransformTranslate(transform, 0, self.size.height);
transform = CGAffineTransformRotate(transform, -M_PI_2);
break;
case UIImageOrientationUp:
case UIImageOrientationUpMirrored:
break;
}


switch (self.imageOrientation) {
case UIImageOrientationUpMirrored:
case UIImageOrientationDownMirrored:
transform = CGAffineTransformTranslate(transform, self.size.width, 0);
transform = CGAffineTransformScale(transform, -1, 1);
break;


case UIImageOrientationLeftMirrored:
case UIImageOrientationRightMirrored:
transform = CGAffineTransformTranslate(transform, self.size.height, 0);
transform = CGAffineTransformScale(transform, -1, 1);
break;
case UIImageOrientationUp:
case UIImageOrientationDown:
case UIImageOrientationLeft:
case UIImageOrientationRight:
break;
}


// Now we draw the underlying CGImage into a new context, applying the transform
// calculated above.
CGContextRef ctx = CGBitmapContextCreate(NULL, self.size.width, self.size.height,
CGImageGetBitsPerComponent(self.CGImage), 0,
CGImageGetColorSpace(self.CGImage),
CGImageGetBitmapInfo(self.CGImage));
CGContextConcatCTM(ctx, transform);
switch (self.imageOrientation) {
case UIImageOrientationLeft:
case UIImageOrientationLeftMirrored:
case UIImageOrientationRight:
case UIImageOrientationRightMirrored:
// Grr...
CGContextDrawImage(ctx, CGRectMake(0,0,self.size.height,self.size.width), self.CGImage);
break;


default:
CGContextDrawImage(ctx, CGRectMake(0,0,self.size.width,self.size.height), self.CGImage);
break;
}


// And now we just create a new UIImage from the drawing context
CGImageRef cgimg = CGBitmapContextCreateImage(ctx);
UIImage *img = [UIImage imageWithCGImage:cgimg];
CGContextRelease(ctx);
CGImageRelease(cgimg);
return img;
}


@end
小开

我想出了一个更简单的方法:

- (UIImage *)normalizedImage {
if (self.imageOrientation == UIImageOrientationUp) return self;


UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
[self drawInRect:(CGRect){0, 0, self.size}];
UIImage *normalizedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return normalizedImage;
}

顺便说一句:@Anomie的代码不考虑scale，所以不适用于2x图像。

小开

这是我发现的固定方向问题

UIImage *initialImage = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
NSData *data = UIImagePNGRepresentation(self.initialImage);


UIImage *tempImage = [UIImage imageWithData:data];
UIImage *fixedOrientationImage = [UIImage imageWithCGImage:tempImage.CGImage
scale:initialImage.scale
orientation:self.initialImage.imageOrientation];
initialImage = fixedOrientationImage;

编辑:

UIImage *initialImage = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
NSData *data = UIImagePNGRepresentation(self.initialImage);


initialImage = [UIImage imageWithCGImage:[UIImage imageWithData:data].CGImage
scale:initialImage.scale
orientation:self.initialImage.imageOrientation];
小开

我在设计我的应用程序拍照时使用了这个页面，我发现以下方法将纠正方向，并且比以前的答案使用更少的内存和处理器:

CGImageRef cgRef = image.CGImage;
image = [[UIImage alloc] initWithCGImage:cgRef scale:1.0 orientation:UIImageOrientationUp];

这基本上只是用一个新的方向重新包装实际的图像数据。我使用@an0的代码，但它使一个新的图像在内存中，这可能是一个326x2448的图像，你可能会从相机。

小开

如果你启用了编辑，那么编辑后的图像(与原始图像相反)将按照预期的方向:

UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
imagePickerController.allowsEditing = YES;
// set delegate and present controller


- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
UIImage *photo = [info valueForKey:UIImagePickerControllerEditedImage];
// do whatever
}

启用编辑功能允许用户在点击“使用照片”之前调整图像大小和移动图像

小开

迅捷;)

更新swift 3.0: d

func sFunc_imageFixOrientation(img:UIImage) -> UIImage {




// No-op if the orientation is already correct
if (img.imageOrientation == UIImageOrientation.up) {
return img;
}
// We need to calculate the proper transformation to make the image upright.
// We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
var transform:CGAffineTransform = CGAffineTransform.identity


if (img.imageOrientation == UIImageOrientation.down
|| img.imageOrientation == UIImageOrientation.downMirrored) {


transform = transform.translatedBy(x: img.size.width, y: img.size.height)
transform = transform.rotated(by: CGFloat(M_PI))
}


if (img.imageOrientation == UIImageOrientation.left
|| img.imageOrientation == UIImageOrientation.leftMirrored) {


transform = transform.translatedBy(x: img.size.width, y: 0)
transform = transform.rotated(by: CGFloat(M_PI_2))
}


if (img.imageOrientation == UIImageOrientation.right
|| img.imageOrientation == UIImageOrientation.rightMirrored) {


transform = transform.translatedBy(x: 0, y: img.size.height);
transform = transform.rotated(by: CGFloat(-M_PI_2));
}


if (img.imageOrientation == UIImageOrientation.upMirrored
|| img.imageOrientation == UIImageOrientation.downMirrored) {


transform = transform.translatedBy(x: img.size.width, y: 0)
transform = transform.scaledBy(x: -1, y: 1)
}


if (img.imageOrientation == UIImageOrientation.leftMirrored
|| img.imageOrientation == UIImageOrientation.rightMirrored) {


transform = transform.translatedBy(x: img.size.height, y: 0);
transform = transform.scaledBy(x: -1, y: 1);
}




// Now we draw the underlying CGImage into a new context, applying the transform
// calculated above.
let ctx:CGContext = CGContext(data: nil, width: Int(img.size.width), height: Int(img.size.height),
bitsPerComponent: img.cgImage!.bitsPerComponent, bytesPerRow: 0,
space: img.cgImage!.colorSpace!,
bitmapInfo: img.cgImage!.bitmapInfo.rawValue)!


ctx.concatenate(transform)




if (img.imageOrientation == UIImageOrientation.left
|| img.imageOrientation == UIImageOrientation.leftMirrored
|| img.imageOrientation == UIImageOrientation.right
|| img.imageOrientation == UIImageOrientation.rightMirrored
) {




ctx.draw(img.cgImage!, in: CGRect(x:0,y:0,width:img.size.height,height:img.size.width))


} else {
ctx.draw(img.cgImage!, in: CGRect(x:0,y:0,width:img.size.width,height:img.size.height))
}




// And now we just create a new UIImage from the drawing context
let cgimg:CGImage = ctx.makeImage()!
let imgEnd:UIImage = UIImage(cgImage: cgimg)


return imgEnd
}
小开

以下是@an0给出的答案的Swift版本:

func normalizedImage() -> UIImage {


if (self.imageOrientation == UIImageOrientation.Up) {
return self;
}


UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale);
let rect = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)
self.drawInRect(rect)


let normalizedImage : UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext();
return normalizedImage;
}

也可以用在更一般的函数中:

func fixOrientation(img:UIImage) -> UIImage {


if (img.imageOrientation == UIImageOrientation.Up) {
return img;
}


UIGraphicsBeginImageContextWithOptions(img.size, false, img.scale);
let rect = CGRect(x: 0, y: 0, width: img.size.width, height: img.size.height)
img.drawInRect(rect)


let normalizedImage : UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext();
return normalizedImage;


}

Swift 3版本:

func fixOrientation(img: UIImage) -> UIImage {
if (img.imageOrientation == .up) {
return img
}


UIGraphicsBeginImageContextWithOptions(img.size, false, img.scale)
let rect = CGRect(x: 0, y: 0, width: img.size.width, height: img.size.height)
img.draw(in: rect)


let normalizedImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()


return normalizedImage
}
小开

这是swift的UIImage扩展:

extension UIImage {


func fixOrientation() -> UIImage {


// No-op if the orientation is already correct
if ( self.imageOrientation == UIImageOrientation.Up ) {
return self;
}


// We need to calculate the proper transformation to make the image upright.
// We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
var transform: CGAffineTransform = CGAffineTransformIdentity


if ( self.imageOrientation == UIImageOrientation.Down || self.imageOrientation == UIImageOrientation.DownMirrored ) {
transform = CGAffineTransformTranslate(transform, self.size.width, self.size.height)
transform = CGAffineTransformRotate(transform, CGFloat(M_PI))
}


if ( self.imageOrientation == UIImageOrientation.Left || self.imageOrientation == UIImageOrientation.LeftMirrored ) {
transform = CGAffineTransformTranslate(transform, self.size.width, 0)
transform = CGAffineTransformRotate(transform, CGFloat(M_PI_2))
}


if ( self.imageOrientation == UIImageOrientation.Right || self.imageOrientation == UIImageOrientation.RightMirrored ) {
transform = CGAffineTransformTranslate(transform, 0, self.size.height);
transform = CGAffineTransformRotate(transform,  CGFloat(-M_PI_2));
}


if ( self.imageOrientation == UIImageOrientation.UpMirrored || self.imageOrientation == UIImageOrientation.DownMirrored ) {
transform = CGAffineTransformTranslate(transform, self.size.width, 0)
transform = CGAffineTransformScale(transform, -1, 1)
}


if ( self.imageOrientation == UIImageOrientation.LeftMirrored || self.imageOrientation == UIImageOrientation.RightMirrored ) {
transform = CGAffineTransformTranslate(transform, self.size.height, 0);
transform = CGAffineTransformScale(transform, -1, 1);
}


// Now we draw the underlying CGImage into a new context, applying the transform
// calculated above.
var ctx: CGContextRef = CGBitmapContextCreate(nil, Int(self.size.width), Int(self.size.height),
CGImageGetBitsPerComponent(self.CGImage), 0,
CGImageGetColorSpace(self.CGImage),
CGImageGetBitmapInfo(self.CGImage));


CGContextConcatCTM(ctx, transform)


if ( self.imageOrientation == UIImageOrientation.Left ||
self.imageOrientation == UIImageOrientation.LeftMirrored ||
self.imageOrientation == UIImageOrientation.Right ||
self.imageOrientation == UIImageOrientation.RightMirrored ) {
CGContextDrawImage(ctx, CGRectMake(0,0,self.size.height,self.size.width), self.CGImage)
} else {
CGContextDrawImage(ctx, CGRectMake(0,0,self.size.width,self.size.height), self.CGImage)
}


// And now we just create a new UIImage from the drawing context and return it
return UIImage(CGImage: CGBitmapContextCreateImage(ctx))!
}
}

基于MetalHeart2003的早期工作。

小开

解决了Swift 3.1的方向问题，同时从相机捕捉图像。

我更新了杰克和金属之心给出的解决方案

用户界面图像扩展

//MARK:- Image Orientation fix


extension UIImage {


func fixOrientation() -> UIImage {


// No-op if the orientation is already correct
if ( self.imageOrientation == UIImageOrientation.up ) {
return self;
}


// We need to calculate the proper transformation to make the image upright.
// We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
var transform: CGAffineTransform = CGAffineTransform.identity


if ( self.imageOrientation == UIImageOrientation.down || self.imageOrientation == UIImageOrientation.downMirrored ) {
transform = transform.translatedBy(x: self.size.width, y: self.size.height)
transform = transform.rotated(by: CGFloat(Double.pi))
}


if ( self.imageOrientation == UIImageOrientation.left || self.imageOrientation == UIImageOrientation.leftMirrored ) {
transform = transform.translatedBy(x: self.size.width, y: 0)
transform = transform.rotated(by: CGFloat(Double.pi / 2.0))
}


if ( self.imageOrientation == UIImageOrientation.right || self.imageOrientation == UIImageOrientation.rightMirrored ) {
transform = transform.translatedBy(x: 0, y: self.size.height);
transform = transform.rotated(by: CGFloat(-Double.pi / 2.0));
}


if ( self.imageOrientation == UIImageOrientation.upMirrored || self.imageOrientation == UIImageOrientation.downMirrored ) {
transform = transform.translatedBy(x: self.size.width, y: 0)
transform = transform.scaledBy(x: -1, y: 1)
}


if ( self.imageOrientation == UIImageOrientation.leftMirrored || self.imageOrientation == UIImageOrientation.rightMirrored ) {
transform = transform.translatedBy(x: self.size.height, y: 0);
transform = transform.scaledBy(x: -1, y: 1);
}


// Now we draw the underlying CGImage into a new context, applying the transform
// calculated above.
let ctx: CGContext = CGContext(data: nil, width: Int(self.size.width), height: Int(self.size.height),
bitsPerComponent: self.cgImage!.bitsPerComponent, bytesPerRow: 0,
space: self.cgImage!.colorSpace!,
bitmapInfo: self.cgImage!.bitmapInfo.rawValue)!;


ctx.concatenate(transform)


if ( self.imageOrientation == UIImageOrientation.left ||
self.imageOrientation == UIImageOrientation.leftMirrored ||
self.imageOrientation == UIImageOrientation.right ||
self.imageOrientation == UIImageOrientation.rightMirrored ) {
ctx.draw(self.cgImage!, in: CGRect(x: 0,y: 0,width: self.size.height,height: self.size.width))
} else {
ctx.draw(self.cgImage!, in: CGRect(x: 0,y: 0,width: self.size.width,height: self.size.height))
}


// And now we just create a new UIImage from the drawing context and return it
return UIImage(cgImage: ctx.makeImage()!)
}
}

斯威夫特2.0

//MARK:- Image Orientation fix


extension UIImage {


func fixOrientation() -> UIImage {


// No-op if the orientation is already correct
if ( self.imageOrientation == UIImageOrientation.Up ) {
return self;
}


// We need to calculate the proper transformation to make the image upright.
// We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
var transform: CGAffineTransform = CGAffineTransformIdentity


if ( self.imageOrientation == UIImageOrientation.Down || self.imageOrientation == UIImageOrientation.DownMirrored ) {
transform = CGAffineTransformTranslate(transform, self.size.width, self.size.height)
transform = CGAffineTransformRotate(transform, CGFloat(M_PI))
}


if ( self.imageOrientation == UIImageOrientation.Left || self.imageOrientation == UIImageOrientation.LeftMirrored ) {
transform = CGAffineTransformTranslate(transform, self.size.width, 0)
transform = CGAffineTransformRotate(transform, CGFloat(M_PI_2))
}


if ( self.imageOrientation == UIImageOrientation.Right || self.imageOrientation == UIImageOrientation.RightMirrored ) {
transform = CGAffineTransformTranslate(transform, 0, self.size.height);
transform = CGAffineTransformRotate(transform,  CGFloat(-M_PI_2));
}


if ( self.imageOrientation == UIImageOrientation.UpMirrored || self.imageOrientation == UIImageOrientation.DownMirrored ) {
transform = CGAffineTransformTranslate(transform, self.size.width, 0)
transform = CGAffineTransformScale(transform, -1, 1)
}


if ( self.imageOrientation == UIImageOrientation.LeftMirrored || self.imageOrientation == UIImageOrientation.RightMirrored ) {
transform = CGAffineTransformTranslate(transform, self.size.height, 0);
transform = CGAffineTransformScale(transform, -1, 1);
}


// Now we draw the underlying CGImage into a new context, applying the transform
// calculated above.
let ctx: CGContextRef = CGBitmapContextCreate(nil, Int(self.size.width), Int(self.size.height),
CGImageGetBitsPerComponent(self.CGImage), 0,
CGImageGetColorSpace(self.CGImage),
CGImageGetBitmapInfo(self.CGImage).rawValue)!;


CGContextConcatCTM(ctx, transform)


if ( self.imageOrientation == UIImageOrientation.Left ||
self.imageOrientation == UIImageOrientation.LeftMirrored ||
self.imageOrientation == UIImageOrientation.Right ||
self.imageOrientation == UIImageOrientation.RightMirrored ) {
CGContextDrawImage(ctx, CGRectMake(0,0,self.size.height,self.size.width), self.CGImage)
} else {
CGContextDrawImage(ctx, CGRectMake(0,0,self.size.width,self.size.height), self.CGImage)
}


// And now we just create a new UIImage from the drawing context and return it
return UIImage(CGImage: CGBitmapContextCreateImage(ctx)!)
}
}

在你的代码中使用这个UIImage扩展:

让fixOrientationImage = chosenImage.fixOrientation ()

像这样把它放在图像选择器的委托方法中

斯威夫特3.1

//MARK: Image Picker Delegates
func imagePickerController(
_ picker: UIImagePickerController,
didFinishPickingMediaWithInfo info: [String : Any]){
let chosenImage = info[UIImagePickerControllerOriginalImage] as! UIImage
profileImg.contentMode = .scaleAspectFill
let fixOrientationImage=chosenImage.fixOrientation()
profileImg.image = fixOrientationImage


dismiss(animated: true, completion: nil)
}

斯威夫特2.0

//MARK: Image Picker Delegates
func imagePickerController(
picker: UIImagePickerController,
didFinishPickingMediaWithInfo info: [String : AnyObject])
{
let chosenImage = info[UIImagePickerControllerOriginalImage] as! UIImage
profileImg.contentMode = .ScaleAspectFill
**//Fix the image orientation**
let fixOrientationImage=chosenImage.fixOrientation()
profileImg.image = fixOrientationImage


dismissViewControllerAnimated(true, completion: nil)
}
小开

这是一个基于@Anomie接受的答案的Swift 2的UIImage扩展。它使用了更清晰的开关外壳。它还会考虑CGBitmapContextCreateImage()返回的可选值。

extension UIImage {
func rotateImageByOrientation() -> UIImage {
// No-op if the orientation is already correct
guard self.imageOrientation != .Up else {
return self
}


// We need to calculate the proper transformation to make the image upright.
// We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
var transform = CGAffineTransformIdentity;


switch (self.imageOrientation) {
case .Down, .DownMirrored:
transform = CGAffineTransformTranslate(transform, self.size.width, self.size.height)
transform = CGAffineTransformRotate(transform, CGFloat(M_PI))


case .Left, .LeftMirrored:
transform = CGAffineTransformTranslate(transform, self.size.width, 0)
transform = CGAffineTransformRotate(transform, CGFloat(M_PI_2))


case .Right, .RightMirrored:
transform = CGAffineTransformTranslate(transform, 0, self.size.height)
transform = CGAffineTransformRotate(transform, CGFloat(-M_PI_2))


default:
break
}


switch (self.imageOrientation) {
case .UpMirrored, .DownMirrored:
transform = CGAffineTransformTranslate(transform, self.size.width, 0)
transform = CGAffineTransformScale(transform, -1, 1)


case .LeftMirrored, .RightMirrored:
transform = CGAffineTransformTranslate(transform, self.size.height, 0)
transform = CGAffineTransformScale(transform, -1, 1)


default:
break
}


// Now we draw the underlying CGImage into a new context, applying the transform
// calculated above.
let ctx = CGBitmapContextCreate(nil, Int(self.size.width), Int(self.size.height),
CGImageGetBitsPerComponent(self.CGImage), 0,
CGImageGetColorSpace(self.CGImage),
CGImageGetBitmapInfo(self.CGImage).rawValue)
CGContextConcatCTM(ctx, transform)
switch (self.imageOrientation) {
case .Left, .LeftMirrored, .Right, .RightMirrored:
CGContextDrawImage(ctx, CGRectMake(0,0,self.size.height,self.size.width), self.CGImage)


default:
CGContextDrawImage(ctx, CGRectMake(0,0,self.size.width,self.size.height), self.CGImage)
}


// And now we just create a new UIImage from the drawing context
if let cgImage = CGBitmapContextCreateImage(ctx) {
return UIImage(CGImage: cgImage)
} else {
return self
}
}
}
小开

如果我没理解错的话，你想做的是忽略UIImage的方向?如果是这样，那么你可以这样做:-

//image is your original image
image = [UIImage imageWithCGImage:[image CGImage]
scale:[image scale]
orientation: UIImageOrientationUp];

或者用Swift:-

image = UIImage(CGImage: image.CGImage!, scale: image.scale, orientation:.Up)

它解决了我的裁剪问题。霍普，这就是你要找的…

小开

Swift 3版本基于@jake1981，他从@MetalHeart2003中获得了它

extension UIImage {


func fixOrientation() -> UIImage {


// No-op if the orientation is already correct
if ( self.imageOrientation == UIImageOrientation.up ) {
return self;
}


// We need to calculate the proper transformation to make the image upright.
// We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.


var transform: CGAffineTransform = CGAffineTransform.identity


if ( self.imageOrientation == UIImageOrientation.down || self.imageOrientation == UIImageOrientation.downMirrored ) {
transform = transform.translatedBy(x: self.size.width, y: self.size.height)
transform = transform.rotated(by: CGFloat(M_PI))
}


if ( self.imageOrientation == UIImageOrientation.left || self.imageOrientation == UIImageOrientation.leftMirrored ) {
transform = transform.translatedBy(x: self.size.width, y: 0)
transform = transform.rotated(by: CGFloat(M_PI_2))
}


if ( self.imageOrientation == UIImageOrientation.right || self.imageOrientation == UIImageOrientation.rightMirrored ) {
transform = transform.translatedBy(x: 0, y: self.size.height);
transform = transform.rotated(by: CGFloat(-M_PI_2));
}


if ( self.imageOrientation == UIImageOrientation.upMirrored || self.imageOrientation == UIImageOrientation.downMirrored ) {
transform = transform.translatedBy(x: self.size.width, y: 0)
transform = transform.scaledBy(x: -1, y: 1)
}


if ( self.imageOrientation == UIImageOrientation.leftMirrored || self.imageOrientation == UIImageOrientation.rightMirrored ) {
transform = transform.translatedBy(x: self.size.height, y: 0);
transform = transform.scaledBy(x: -1, y: 1);
}


// Now we draw the underlying CGImage into a new context, applying the transform
// calculated above.
let ctx: CGContext = CGContext(data: nil, width: Int(self.size.width), height: Int(self.size.height),
bitsPerComponent: self.cgImage!.bitsPerComponent, bytesPerRow: 0,
space: self.cgImage!.colorSpace!,
bitmapInfo: self.cgImage!.bitmapInfo.rawValue)!
ctx.concatenate(transform)


if ( self.imageOrientation == UIImageOrientation.left ||
self.imageOrientation == UIImageOrientation.leftMirrored ||
self.imageOrientation == UIImageOrientation.right ||
self.imageOrientation == UIImageOrientation.rightMirrored ) {


ctx.draw(self.cgImage!, in: CGRect(x: 0, y: 0, width: self.size.height, height: self.size.width))
} else {
ctx.draw(self.cgImage!, in: CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height))
}


// And now we just create a new UIImage from the drawing context and return it
return UIImage(cgImage: ctx.makeImage()!)


}
}
小开

基于Sourabh Sharma的答案更新Swift 3.1，并清理了代码。

extension UIImage {
func fixedOrientation() -> UIImage {
if imageOrientation == .up { return self }


var transform:CGAffineTransform = .identity
switch imageOrientation {
case .down, .downMirrored:
transform = transform.translatedBy(x: size.width, y: size.height).rotated(by: .pi)
case .left, .leftMirrored:
transform = transform.translatedBy(x: size.width, y: 0).rotated(by: .pi/2)
case .right, .rightMirrored:
transform = transform.translatedBy(x: 0, y: size.height).rotated(by: -.pi/2)
default: break
}


switch imageOrientation {
case .upMirrored, .downMirrored:
transform = transform.translatedBy(x: size.width, y: 0).scaledBy(x: -1, y: 1)
case .leftMirrored, .rightMirrored:
transform = transform.translatedBy(x: size.height, y: 0).scaledBy(x: -1, y: 1)
default: break
}


let ctx = CGContext(data: nil, width: Int(size.width), height: Int(size.height),
bitsPerComponent: cgImage!.bitsPerComponent, bytesPerRow: 0,
space: cgImage!.colorSpace!, bitmapInfo: cgImage!.bitmapInfo.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))
}
return UIImage(cgImage: ctx.makeImage()!)
}
}

选取器委托方法示例:

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
guard let originalImage = info[UIImagePickerControllerOriginalImage] as? UIImage else { return }
let fixedImage = originalImage.fixedOrientation()
// do your work
}
小开

我经历过这个问题，从相机拍摄的图像或保存在相机卷从相机。从safari浏览器在图片库中下载的图像上传时不会旋转。

我能够通过在上传之前将图像数据制作为JPEG来解决这个问题。

let image = info[UIImagePickerControllerOriginalImage] as! UIImage
let data = UIImageJPEGRepresentation(image, 1.0)

我们现在可以使用数据进行上传，上传后图像不会旋转。

希望这能奏效。

小开

Swift 4.x/5.0版本的@an0的解决方案:

extension UIImage {
func upOrientationImage() -> UIImage? {
switch imageOrientation {
case .up:
return self
default:
UIGraphicsBeginImageContextWithOptions(size, false, scale)
draw(in: CGRect(origin: .zero, size: size))
let result = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return result
}
}
}
小开 
@an0, thanks for the answer!
The only thing is autoreleasepool:


func fixOrientation(img: UIImage) -> UIImage? {


let result: UIImage?
if img.imageOrientation == .up {
result = img
} else {


result = autoreleasepool { () -> UIImage? in
UIGraphicsBeginImageContextWithOptions(img.size, false, img.scale)
let rect = CGRect(x: 0, y: 0, width: img.size.width, height: img.size.height)
img.draw(in: rect)


let normalizedImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()


return normalizedImage
}
}


return result
}
小开
下面是Swift-4.2代码，用于自动修复图像方向 返回界面图像< / p > 
func AutofixImageOrientation(_ image: UIImage)->UIImage {


UIGraphicsBeginImageContext(image.size)


image.draw(at: .zero)


let newImage = UIGraphicsGetImageFromCurrentImageContext()


UIGraphicsEndImageContext()


return newImage ?? image
}
小开

我把这个换成了Xamarin:

private static UIImage FixImageOrientation(UIImage image)
{
if (image.Orientation == UIImageOrientation.Up)
{
return image;
}


var transform = CGAffineTransform.MakeIdentity();


float pi = (float)Math.PI;


switch (image.Orientation)
{
case UIImageOrientation.Down:
case UIImageOrientation.DownMirrored:
transform = CGAffineTransform.Translate(transform, image.Size.Width, image.Size.Height);
transform = CGAffineTransform.Rotate(transform, pi);
break;


case UIImageOrientation.Left:
case UIImageOrientation.LeftMirrored:
transform = CGAffineTransform.Translate(transform, image.Size.Width, 0);
transform = CGAffineTransform.Rotate(transform, pi / 2);
break;


case UIImageOrientation.Right:
case UIImageOrientation.RightMirrored:
transform = CGAffineTransform.Translate(transform, 0, image.Size.Height);
transform = CGAffineTransform.Rotate(transform, -(pi / 2));
break;
}


switch (image.Orientation)
{
case UIImageOrientation.UpMirrored:
case UIImageOrientation.DownMirrored:
transform = CGAffineTransform.Translate(transform, image.Size.Width, 0);
transform = CGAffineTransform.Scale(transform, -1, 1);
break;


case UIImageOrientation.LeftMirrored:
case UIImageOrientation.RightMirrored:
transform = CGAffineTransform.Translate(transform, image.Size.Height, 0);
transform = CGAffineTransform.Scale(transform, -1, 1);
break;
}


var ctx = new CGBitmapContext(null, (nint)image.Size.Width, (nint)image.Size.Height, image.CGImage.BitsPerComponent,
image.CGImage.BytesPerRow, image.CGImage.ColorSpace, image.CGImage.BitmapInfo);


ctx.ConcatCTM(transform);


switch (image.Orientation)
{
case UIImageOrientation.Left:
case UIImageOrientation.LeftMirrored:
case UIImageOrientation.Right:
case UIImageOrientation.RightMirrored:
ctx.DrawImage(new CGRect(0, 0, image.Size.Height, image.Size.Width), image.CGImage);
break;


default:
ctx.DrawImage(new CGRect(0, 0, image.Size.Width, image.Size.Height), image.CGImage);
break;
}


var cgimg = ctx.ToImage();
var img = new UIImage(cgimg);


ctx.Dispose();
ctx = null;
cgimg.Dispose();
cgimg = null;


return img;
}
小开

我通过在下面写几行代码来实现这一点

extension UIImage {


public func correctlyOrientedImage() -> UIImage {
guard imageOrientation != .up else { return self }


UIGraphicsBeginImageContextWithOptions(size, false, scale)
draw(in: CGRect(origin: .zero, size: size))
let normalizedImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()


return normalizedImage
}
}
小开

这是一个解决方案，不会改变颜色空间的原始图像。如果你想规范化一个灰度图像的方向，你没有所有基于UIGraphicsBeginImageContextWithOptions的解决方案，因为它在RGB颜色空间中创建了一个上下文。相反，你必须创建一个具有与原始图像相同属性的上下文并绘制:

extension UIImage {
static let rotatedOrentations: [UIImage.Orientation] = [.left, .leftMirrored, .right, .rightMirrored]


func normalizedImage() -> UIImage {
if imageOrientation == .up {
return self
}


let image = self.cgImage!
let swapOrientation = UIImage.rotatedOrentations.contains(imageOrientation)
let width = swapOrientation ? image.height : image.width
let height = swapOrientation ? image.width : image.height
let context = CGContext(data: nil, width: width, height: height, bitsPerComponent: image.bitsPerComponent, bytesPerRow: image.bytesPerRow, space: image.colorSpace!, bitmapInfo: image.bitmapInfo.rawValue)!
let flipVertical = CGAffineTransform(a: 1, b: 0, c: 0, d: -1, tx: 0, ty: CGFloat(height));
context.concatenate(flipVertical)
UIGraphicsPushContext(context)
self.draw(at: .zero)
UIGraphicsPopContext()


return UIImage(cgImage: context.makeImage()!)
}
}

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