According to MSDN, it is not a particularly good idea to use classes within the System.Drawing namespace in a Windows Service or ASP.NET Service. Now I am d
Even though it's not officially supported, I've used the System.Drawing classes extensively on a high-volume web server (both web application and web services) for years without it causing any performance or reliability problems.
I think the only way to determine if the code is safe to use is to test, monitor, and wrap any object with external resources in using{} statements.