If you are looking for a quick way to accomplish this without getting into too much code check out http://www.roborealm.com/ RoboRealm is an application for use in machine vision, image analysis, and robotic vision systems. Using an easy to use point and click interface RoboRealm simplifies vision programming! Using an inexpensive usb webcam and the PC you already have you can now add machine vision to your robotic projects!
The application has both serial and parallel port modules to send data over those types of devices.
STeven.