confused by the UIImageOrientation of portrait/landscape mode photo

Question

I take two photos using the ios`s system camera,which one is in portrait mode and another is in landscape mode, then I use imagePicker to pick them out in my app like this:

-(void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{

    UIImage* sourceImage = [info objectForKey:UIImagePickerControllerOriginalImage];


    UIImageOrientation imageOrientation = sourceImage.imageOrientation;
    NSLog(@"%d",imageOrientation);

}

Note that I NSLog out the UIImageOrientation value of the image I just picked out. the result is the value for the portrait mode photo is 3(which represents UIImageOrientationRight) and the landscape mode photo is 0 (UIImageOrientationUp) I just do not understand why. can anyone explain that? thanks!

Check out this topic http://stackoverflow.com/questions/10850184/ios-image-get-rotated-90-degree-after-saved-as-png-representation-data — Max Komarychev, Jul 29 '13 at 11:27
This question brought me to the correct answer. That aught to account for an up-vote. — Patricia, Dec 18 '13 at 17:46
That question was down-voted for no valid reason. It's a perfectly valid question — GrandSteph, Dec 18 '14 at 18:49

score 3 · Accepted Answer · answered Jul 29 '13 at 11:32

3

iPhone's camera save photo regardless to the device orientation but it adds a metainformation to image to allow this image rendered properly. imageOrientation describes the amount of degrees the image should be rotated to be properly rendered.

answered Jul 29 '13 at 11:32

Max Komarychev

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Thanks @Max K.! so the UIImageOrientationRight for portrait photo means the system has to rotate the image CCW 90 degree to render it properly? – wdanxna Jul 29 '13 at 12:00
1

Yes, please, look at the `UIImage` reference for more information http://developer.apple.com/library/ios/#documentation/UIKit/Reference/UIImage_Class/Reference/Reference.html. Read carefully to understand what those constants actually mean. – Max Komarychev Jul 29 '13 at 13:38
it's incredibly confusing/strange that it seems to save as a landscape?? so the always-default portrait mode is UIImageOrientationRight. I think. – Fattie Mar 09 '14 at 12:09

confused by the UIImageOrientation of portrait/landscape mode photo

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