UIImage created from CGImageRef fails with UIImagePNGRepresentation

Posted by Ari J.R. on Stack Overflow See other posts from Stack Overflow or by Ari J.R.
Published on 2010-02-10T21:13:20Z Indexed on 2010/05/01 4:07 UTC
Read the original article Hit count: 272

Filed under:
|
|
|

I'm using the following code to crop and create a new UIImage out of a bigger one. I've isolated the issue to be with the function CGImageCreateWithImageInRect() which seem to not set some CGImage property the way I want. :-) The problem is that a call to function UIImagePNGRepresentation() fails returning a nil.

CGImageRef origRef = [stillView.image CGImage];
CGImageRef cgCrop = CGImageCreateWithImageInRect( origRef, theRect);
UIImage *imgCrop = [UIImage imageWithCGImage:cgCrop];

...

NSData *data = UIImagePNGRepresentation ( imgCrop);

-- libpng error: No IDATs written into file

Any idea what might wrong or alternative for cropping a rect out of UIImage? Many thanks!

© Stack Overflow or respective owner

Related posts about iphone

Related posts about uiimage