“I am looking for a camera that rejects parts with incorrect drill-holes.” Every day, machine vision providers receive such inquiries. Often, prospective customers are surprised at the answer: “Sorry, but cameras can’t do that.”
At first glance, the camera is the source of the image. But actually, the image is created by the illumination. The charge-coupled device (CCD) chip transforms the photons encountering it into an electrical signal. The camera electronics digitize this electrical signal and make it available as a “raw digital image.”
The computer-or rather the software it runs-uses this raw digital image for two basic tasks: visualization and automatic image analysis. Automatic image analysis is, however, only reliable in the case of controlled illumination and simple objects. In the context of visualization, the illumination’s influence on the resulting image should not be underestimated.