Preserving alpha issues with loaded UIImages - how to avoid discarding alpha values on import?

Posted by Peter Hajas on Stack Overflow See other posts from Stack Overflow or by Peter Hajas
Published on 2010-05-06T23:01:35Z Indexed on 2010/05/06 23:08 UTC
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uiimage

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uiimageview

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alphablending

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alpha

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iphone-sdk-3.0

My application lets the user save/load images with alpha values to the camera roll on the device. I can see in the Photos application that these images are appropriately alpha'd, as alpha'd areas just appear black. However, when I load these images back into the application using the valueForKey:UIImagePickerControllerOriginalImage message to the info dictionary from (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info, the alpha values are turned to just white, making those sections opaque. Is there a way to preserve these alpha values?

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