UIImage in iOS 5, Orientation and Resize

One of the things I found very strange is the fact that most operations that came with iOS prior iOS 5 which revolved around UIImage didn’t take into account the orientation of the image. This meant that if you want to read a picture from the camera roll and resize it, you’d have to roll your own code to correctly flip and/or rotate the image according to its orientation value.

Being my lazy self I used the fine code of Trevor Harmon in UIImage+Resize. Trevor added some categories to make handling UIImage a bit nicer. The code takes create of everything including orientation.

My app worked great on iOS 4 and early betas of iOS 5, however in the late beta of iOS 5 and in the release it wrongfully rotated the images.

After further investigation it seems iOS 5 already rotates the image correctly. UIImage+Resize rotated it again, causing the images to get skewed.
A quick fix would simply avoid the transposition code in UIImage+Resize.

Since the code ran perfectly fine in iOS 4, for backwards compatibility I added a check for OS version and for anything below 5.0 the old code would work.
Check out this gist:

For better performance I would store a boolean flag somewhere in the app saying you are running in iOS 5 and check that instead of keep on checking the OS version every run, but this is just to get you started.