Add styles to dynamically downloaded images in iOS app

My question is: Since I have an app that downloads images from TMDB (the movie database) and I can't edit them in Photoshop before adding them to my application I was wondering if there was a way to add effects. Like a nice drop shadow and a 1 pix border to my images dynamically as they are downloaded or referenced from within application? (during development)

I can't seem to find a way to do this. I'm prob开发者_运维问答ably looking in the wrong place though. Any help?

You can easily do all that using Quartz.