Objective measure of woven fabric’s cover factor by image processing

Abstract Digital image processing techniques are applied to perform an automatic method for the objective measure of woven fabric’s cover factor. Based on a frequency domain analysis, digital images of woven fabric samples, obtained with a camera assembled to a microscope, are cropped to enclose the maximum integer number of warp and weft periods and leveled for non-uniform illumination. Posterior thresholding, designed to perform suitably for both high and low cover factor fabric samples, gives rise to the objective value. The method has been applied to three different sets of samples manufactured in plain weave, with known yarn numbers and thread counts. Cover factors obtained by this method show good correlation with those obtained by a set of visual observers and are consistent with woven fabric parameters: yarn numbers (tex) and thread counts (yarns/cm). The procedure can be useful to monitor mean cover factor as well as cover factor variability in fabric batches. It does not require sophisticated equipment and can be straightforwardly implemented in a textile analysis laboratory.