UIImagePNGRepresentation … writeToFile is always landscape

问题

Each time I use the camera to take a photograph, then save it the image is always in landscape. This means the UIImageView in my Xib is the wrong way around. Its Portrait - which is what I want and expected. I can correct this by rotating the image 90 degrees but even then I can't disable the animation which shows the original landscape photo followed by the animated rotation itself. How can I ensure the UIImageView from the camera is actually in portrait mode when saved and not landscape and, how can I disable the animation during the CGAffineTranformationMakeRotation ??

回答1:

I found this post to be very helpful, it describes adding a category to UIImage to do the rotation of the image before you save it:

http://www.platinumball.net/blog/2009/03/30/iphone-uiimage-rotation-and-mirroring/

And then once the category is implemented, you would do something like this:

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info 
{
    UIImage *originalImage, *editedImage, *rotatedImage;

    editedImage = (UIImage *)[info objectForKey:UIImagePickerControllerEditedImage];
    originalImage = (UIImage *)[info objectForKey:UIImagePickerControllerOriginalImage];

    if (editedImage) 
    {
        rotatedImage = [editedImage rotate:UIImageOrientationRight];
    } 
    else 
    {
        rotatedImage = [originalImage rotate:UIImageOrientationRight];
    }

    NSString *f = @"/set/this/to/your/file/name"; 
    [UIImagePNGRepresentation(rotatedImage) writeToFile:f atomically:YES];

    [[picker parentViewController] dismissModalViewControllerAnimated:YES];
    [picker release];
}

来源：https://stackoverflow.com/questions/6358559/uiimagepngrepresentation-writetofile-is-always-landscape