In case you want to use your webcam as input device for grabbing and processing images, this blog post has some pieces of information which might be valuable for you.
Last week I've discovered that you can use OpenCV to grab images from your webcam quite easily, all you need is the starting point project on github and a valid openCV installation for your system. Maybe you have a look at my previous posting which documents my struggle to get it up and running.
I've learned that in the end it is quite easy to set it up.
On windows you'll just need to download the openCV archive and use the appropriate dll and jar file. On MacOsX you can either compile openCV yourself or use the premade scripts from the macports or homebrew installation systems.
The github project gives you a full setup and self contained program which demonstrates how to use JavaFX to create a simple gui for a image processing application. It shows also how to convert a "Mat" datastructure to a format suitable for JavaFX (without using temporary files), and a Service implementation for the image source. Bottom line is that the picture taken from the webcam will be grabbed by openCV, processed by openCV and displayed with JavaFX.
With this you have the starting point to do more image processing using desktop Java facilities.