Moving parts are usually expensive and seldom maintenance free. Illumination is also a key factor. While LEDs and displays are self-illuminating, your system requires some form of illumination for the other components of the board. The best type of illuminator for this application uses high-frequency diffused neon strip lights. Application-specific virtual instruments developed using National Instruments' IMAQ Vision Library form part of the vision system user interface.
Speed of processing is a critical issue that can directly impact on productivity.
You can consider the overall test as a long sequence of separate elementary tests. Your host PC can do it all, and give you a net gain in terms of reduced software development time and the flexibility to easily reconfigure software. The camera passes colour image information to the acquisition board as three separate RGB analogue signals. The HSL model is not only closer to the human understanding of the concept of colour, but allows the tester system to extract colour information from a single 8-bit plane. You should therefore select a video acquisition board capable of performing this conversion in hardware.