Blur specific part of an image (rectangular, circular)?

Question

I want to blur image rectangular or circular. After googling, I found that it is easy to blur whole image but it difficult to blur specific part of image (rectangular, circu

Answer 1

I know I'm bit late for the party but it may help someone else who struggling to get this working.

I've recently needed to implement it and I couldn't find much info on internet about this specific topic ( specially how to get this working when dealing with different UIImageView's scale types such as Scale to Fill, Center and so on). So I've developed a small project that does exactly what you expect.

https://github.com/pauloubuntu/ios-blur-pan-gesture