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];
存在的问题:
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。手持竖屏拍照时，上传的照片是旋转90度后观看的。
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。
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
}
基于Sourabh Sharma的回答更新了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
}
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()!)
}
}
