Web inspection system

A method of low contrast web inspection of a web, the method comprising the steps of:

• providing at least one smart camera for detecting at least one flaw on the web, wherein detecting the at least one flaw on the web comprises the steps of;
• generating flaw image data of the at least one flaw, the flaw image data comprising an area of pixels having a length and a width;
• generating flaw location data for locating the at least one flaw on the web;
• and
• transmitting the flaw image data and flaw location data over an ethernet to a host computer;
• and
• displaying the flaw image data and flaw location data on the host computer;
• and
• wherein the step of generating the flaw image data and flaw location data comprises the steps of:
• generating a pixel representation of the at least a portion of the web;
• correcting the pixel representation for a lighting uniformity and a pixel sensitivity;
• filtering the corrected pixel representation utilizing a plurality of filters;
• grouping the filtered corrected pixel representations to generate a plurality of potential flaw data streams;
• generating a prioritized data stream from the plurality of potential flaw data streams;
• generating cross direction location data regarding a location of the prioritized data stream;
• generating block data regarding the location of blocks of the prioritized data stream along a machine direction;
• and
• generating the flaw image data from the prioritized data stream of potential flaws utilizing the cross direction location data and the block data.

A web inspection system for detecting a flaw of a plurality of possible flaws on a web, the web inspection system comprising:

• at least one smart camera for generating a digitized video data stream of a flaw on a portion of the web, the at least one smart camera comprising:
• a background filter for averaging the digitized video data stream over a first area of the web to generate an averaged background signal;
• a machine direction streak filter for averaging the digitized video data stream over a distance of the web along a machine direction of the web to generate a filtered machine direction signal;
• a cross direction streak filter for averaging the digitized video data stream over a distance of the web along a cross direction of the web to generate a filtered cross direction signal;
• a first adaptive background subtraction channel for subtracting the averaged background signal from the filtered machine direction signal to generate a first pixel representation;
• a second adaptive background subtraction channel for subtracting the averaged background signal from the filtered cross direction signal to generate a second pixel representation;
• at least one multi-group thresholder for grouping the first and second pixel representations to generate at least two data streams of potential flaws;
• and
• a priority logic circuit for prioritizing the at least two data streams of potential flaws to generate the digitized video data stream of the flaw.