Facebook api: access friends' photos

I've been asked to create a contest page for a radio station. The page should allow users to select a few of their Facebook friends that they want to participate in the prize event. After the friends have been chosen and confirmed the page should generate a collage of the friends' profile pictures.

I know I can get the 200px wide version of anyone's profile picture(assuming it's public) using the graph api. Is there any way to get the picture even开发者_StackOverflow社区 if it isn't public? How about getting a bigger version of it?

I have no experience with the FB developer side, so I will appreciate any links to other useful resources.

Taken from the Facebook Graph API documentation:

You can render the current profile photo for any object by adding the suffix /picture to the object URL. For example, this will render your public profile photo:

<img src="https://graph.facebook.com/facebookid/picture"/>

You can specify the picture size you want with the type argument, which should be one of square (50x50), small (50 pixels wide, variable height), and large (about 200 pixels wide, variable height): http://graph.facebook.com/facebookid/picture?type=large.