检测NSURL是否是UIImage类支持的文件格式的URL

I'm looking for a way to detect a if an NSURL is a URL to a file format supported by the UIImage class, and if yes, open it in something like MWPhotoBrowser (https://github.com/mwaterfall/MWPhotoBrowser) instead of a UIWebView. My first thought is to have an if condition with all the supported file extensions. I'm wondering if anyone knows of a better way?I'm looking for a way to detect a if an NSURL i