A UIImage
has a property imageOrientation
, which instructs the UIImageView
and other UIImage
consumers to rotate the raw image data. There's a good chance that this flag is being saved to the exif data in the uploaded jpeg image, but the program you use to view it is not honoring that flag.
To rotate the UIImage
to display properly when uploaded, you can use a category like this:
UIImage+fixOrientation.h
@interface UIImage (fixOrientation)
- (UIImage *)fixOrientation;
@end
UIImage+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
Recently I faced same issue with my App designed only for iPhone , I had the problem where the launch images would not appear in iPad (On iPad ios >= 7.0.x the launch image is not showing up I get black screen while app is loading (in iPad ios < 7.0.x it works fine )).
I don't face this issue of launch image with iPhone worked fine in all iOS versions.
Solution: Is to update to asset catalog to manage your app's images and target only iOS 6 and Prior.
Steps :
Step 1:
Step 2:
Step 3: on the top right corner click on the 'Attribute Inspector' icon. Here you can set the Target OS for the Launch Images.
Uncheck the iOS 7 check boxes for iPhone, Now you should be able to see the launch images for iPad on iOS >= 7.0.x.
Best Answer
The system loads the launch file before launching the app which creates some constraints on what it can contain (some of which may force you back to static image files):
1.The app is not yet loaded so the view hierarchy does not exist and the system can not call any custom view controller setup code you may have in the app (e.g. viewDidLoad)
2.You can only use standard UIKit classes so you can use UIView or UIViewController but not a custom subclass. If you try to set a custom class you will get an Illegal Configuration error in Xcode.
3.The launch file can only use basic UIKit views such as UIImageView and UILabel. You cannot use a UIWebView.
4.If you are using a storyboard you can specify multiple view controllers but there are again some limitations. For example you can embed view controllers in a navigation or tab bar controller but more complex container classes such as UISplitViewController do not work (at least not yet).
5.Localizing the launch file does not currently seem to have any effect. The base localization is always used so you will probably want to avoid text on the launch screen.
6.You cannot specify different launch files for iPad and iPhone. This may be a problem if you have significantly different interfaces for those devices as there is only so much you can do with auto layout and size classes.
Note that if you are deploying to iOS 7 you will still need to include the static launch image files. You can include both a launch image file and static launch images. Devices such as the iPhone 6 running iOS 8 will use the launch image file whilst iOS 7 devices will fallback to the launch images.