you can realize that with the GD-Lib (look for it at php.net). With that you can create images and write with custom fonts on it. I'm not sure if ttf is supported, but there are a lot of fonts that are. You can look for one that is very similar to the ones you prefer in ttf.
Hope that helps.
And make sure your server supports it as well (with a simple sample-script). Shouldn't be a problem normally, but it's not worth scripting the hole stuff and finding out that it doesn't work on the server afterwards.