Density measurement of yarn dyed woven fabrics based on dual-side scanning and the FFT technique

The yarn density measurement, as part of fabric analysis, is very important for the textile manufacturing process and is traditionally based on single-side analysis. In this paper, a new method, suitable for yarn dyed woven fabrics, is developed, based on dual-side scanning and the fast Fourier transform (FFT) technique for yarn density measurement, instead of one-side image analysis. Firstly, the dual-side scanning method based on the Radon transform (RT) is used for the image registration of both side images of the woven fabric; a lab-used imaging system is established to capture the images of each side. Secondly, the merged image from the dual-side fabric images can be generated using three self-developed image fusion methods. Thirdly, the yarn density can be measured based on the merged image using FFT and inverse fast Fourier transform (IFFT) processing. The effects of yarn color and weave pattern on the density measurement have been investigated for the optimization of the proposed method. Our experimental results show that the proposed method works better than the conventional analysis method in terms of both the accuracy and robustness.