Method and apparatus for measuring crimp frequency of a web

A digital computer based method for characterizing crimp features in a moving web of crimped fibrous material comprising:

• a) using a stepping motor controller ti control the movement of a stroboscopic light source relative to said moving web, and using the emission of light from said stroboscopic light source to create an apparent stop-motion view of said web;
• b) programming and operating a digital computer to determine electronic data representative of a two-dimensional reflected light image of said moving web captured with a video camera, and a video frame grabber for analog to digital conversion, all connected to said digital computer capable of storing two-dimensional digitized images of at least a portion of said moving web in realtime;
• c) measuring and storing the locations and the frequencies of spatial variations in reflected light intensity in said electronic data representative of said two-dimensional reflected light image by means of electronic processing;
• d) classifying by means of electronic processing said stored locations and frequencies of spatial variation in reflected light intensity into categories of base crimp, low frequency oscillations, high frequency oscillations, edge oscillations and unconfirmed oscillations;
• e) processing sequentially by means of electronic processing electronic data representative of said two-dimensional images of said moving web to segment the full width of the web into said categories of base crimp, low frequency oscillations, high frequency oscillations, edge oscillations and unconfirmed oscillations;
• f) displaying by means of electronic processing the categories of spatial frequency of reflected light intensity to derive electronic data representative of each two-dimensional image obtained and stored by means of electronic processing and by further means of electronic processing, locating said base crimp, low frequency oscillations, high frequency oscillations, edge oscillations and unconfirmed oscillations in real time within said electronic data representative of each two-dimensional image correlated with the moving web of crimped fibrous material.