Replace all white/nearly white pixels in a UIImage with alpha using CGImage?

Posted by Peter Hajas on Stack Overflow See other posts from Stack Overflow or by Peter Hajas
Published on 2010-05-12T03:49:21Z Indexed on 2010/05/12 3:54 UTC
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uiimage

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cgimage

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mask

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cgimagemaskcreate

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iphone-sdk-3.0

Hi there,

I have a UIImage with white background. I would like replace the white background/pixels with alpha-transparent pixels. I've looked at other questions on StackOverflow, along with Quartz documentation, but have yet to find a coherent "start-to-end" for this problem. How is this done?

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