MFMailComposeViewController image orientation

Question

I\'m developing a Universal app and I\'m coding for iOS6.

I\'m using the imagePickerController to take a photo and then I am sending it as an attachment using MFMail

Answer 1

I think you can get the UIImage API to handle the rotation for you automatically, without needing to manually do the transforms.

The documentation for the UIImage methods size and drawInRect: both say they take the orientation into account, so I drawInRect the UIImage into a new context and grab the resultant (auto-rotated) image from there. Here's the code in a category:

@interface UIImage (Orientation)

- (UIImage*)imageAdjustedForOrientation;

@end

@implementation UIImage (Orientation)
- (UIImage*)imageAdjustedForOrientation
{
    // The UIImage methods size and drawInRect take into account 
    //  the value of its imageOrientation property
    //  so the rendered image is rotated as necessary.
    UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);

    [self drawInRect:CGRectMake(0, 0, self.size.width, self.size.height)];

    UIImage *orientedImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return orientedImage;
}
@end

I just found this better answer by an0 which is virtually the same, but also includes the optimisation of not re-redrawing the image if the orientation is already correct.