Hello,
Thank you for contacting National Instruments. From your brief description it is a little hard to give you a detailed answer. It sounds like you are interested in doing an inspection application and looking at a PCB for the presense, or lack, of a solder connection. If this is the case, then I would recommend looking into using pattern matching to detect whether that joint is correct or not. There are a number of examples. Below are a few links to some information on this:
Pattern Matching StrategiesAdvanced Pattern Matching ConceptsIf you still have questions or if this is not exactly what you would like to do, then please provide us with more information on your applicaiton, what software you will be using, and what hardware you have.
Regards,
Michael
Applications Engineer
National Instruments