Saving Images without knowing Mime Type

I am using http://img.tweetimag.es/ to pull twitter avatars.

EX: http://img.tweetimag.es/i/joestump_o

How do I know the correct mime type (开发者_如何学运维jpg, png, gif, etc.) to save locally?

Any help would be great, thanks.

JP

Look at the content type of the HTTP GET request. For your example:

Content-Type: image/png

Here are some values you can retrieve, as mentioned in @kgiannakakis answer, take a look at Content-Type:

http://img694.imageshack.us/img694/2144/unledofv.png