Automatic identification of structural characteristics is an important research area for computer aided design of woven fabric.Since the skew is inevitable during fabric scanning

a fast skew detection algorithm based on Hough transform for the fabric surface image is proposed.In order to reduce compute complexity

the information of weft direction is extracted from the gradient of fabric image firstly.Then

hierarchical Hough transform is used to estimate the skew angle of fabric image with satisfactory precision.Finally

based upon the skew detection process

a novel algorithm to identifying the weft density is introduced

which is independent of the image skew.The projection profile on skew angle is used to determine the arrangement of weft yarns

and the density of weft is easily computed.The experimental results show the practicability and efficiency of our method.