cut part image from uiimageview

I have a quick question.

I am trying to draw a shape on a picture and be abl开发者_开发知识库e to cut what is in the circle. Any ideas how I would go about doing that?

You need to use core graphics for that. Create a mask with CGImageMaskCreate, and then use CGImageCreateWithMask to combine mask with the image.
Source and example: How to Mask an Image