Using 23 wool, wool blend and some cellulosic woven fabrics, the different parameters to define the woven fabric cover factor defined by Galceran, Eurotex, Grosberg and Seyam were compared with the cover factor obtained by means of the image analysis. Measurements were carried out on the woven fabrics throughout the different manufacturing stages from the loom to the finished product. Image analysis gives higher cover factors than the speculative parameters proposed and the correlation coefficients observed for the latter were not very high, the highest value not exceeding 0.80. On the other hand image analysis is the sole procedure that furnishes coherent statistical distributions for the cover factor. The best fit was found using the Weibull distribution.