Show photo with SCRATCH OUT EFFECT by finger

I need your help to know how to create an iPhone application to show a photo with SCRATCH OUT EFFECT.

Something like the effect in this flash tutorial http://ww开发者_StackOverfloww.tutorial5.com/content/view/115/46/

Please help. Thanks.

You can have a look at the following post on how to create a blurred image effect, I don't think it's the best & fasted method, but it might get you started:

UIImage blur

You can implement the scratch out effect by using CoreGraphics.

Subclass UIView for the scratchable image. Draw the scratchable image, use a mask to cut out the parts of the image that gets "scratched".

Each time the user scratches the image, make it so the mask and the image gets updated.

Full code example on github