Abstract: A zoned inspection system and method produce inspection results consistent with a user's view of an article by transforming parallel, temporal inspection results from multiple detectors into a serial, spatial domain.

Abstract: An automatic dark level zeroing circuit removes a dark level DC bias from an analog video signal generated by a charge-coupled device (CCD) camera, The automatic dark level zeroing circuit is DC-coupled to the CCD camera such that there is no loss of low frequency information in the analog video signal, The automatic dark level zeroing circuit forms an adaptive feedback loop that removes the dark level DC bias from the analog video signal by using a sampled value of the analog video signal that represents an internally masked pixel to produce a zero correction signal that is then combined with the analog video signal to remove the dark level DC bias without removing any useful video information or otherwise altering the information content of the analog video signal,

Abstract: A web inspection system that inspects a moving web for defects has an enhanced video signal preprocessing capability. The enhanced video signal preprocessing is provided by a preprocessing circuit which has a maximum signal-to-noise (S/N) ratio that is no greater than an inherent maximum S/N ratio of a raw video signal as generated by a charge-coupled device CCD camera. The preprocessing circuit is preferably DC-coupled to the CCD camera to receive the raw video signal and generate an analog filtered video signal using an adaptive feedback loop that preserves a fidelity of the raw video signal in generating the filtered video signal. By improving the video signal preprocessing, the overall defect detection consistency of the web inspection system is improved.