Dynamic measurement of fabric wrinkle recovery angle by video sequence processing

Wrinkle recovery is a dynamic process in which a folded fabric specimen continues to be unfolded by itself, and is often evaluated by angle changes between two folded fabric wings. Inspired by the advantages of video sequence in dynamic measurement, we developed a video capturing and processing system for dynamic measurements of fabric wrinkle recovery angle. In the experiment stage, a wrinkled specimen is first compressed by a pneumatic presser for a certain duration, and then videoed using a charge-couple device camera during its entire recovery process. Each image frame in the video sequence is processed to detect the free wing of the wrinkled specimen. To calculate the recovery angle accurately, image-processing algorithms, such as binarization, thinning operation and Hough transform, are implemented subsequently. Finally, the Wilcoxon rank-sum test is carried out to evaluate the difference between the data measured using the American Association of Textile Chemists and Colorists (AATCC) 66-2008 method and this proposed method. Experimental results indicate that the data calculated by our proposed method are consistent with those ones measured by the AATCC 66-2008 method. Compared with the existing fabric wrinkle recovery measurement devices, such as the SDL-M003 wrinkle recovery tester, the developed measurement system has made three important contributions: (1) it automates the entire testing procedure so that human interference is eliminated; (2) it records the complete change of the wrinkle angle so that the recovery property can be analyzed dynamically; and (3) it uses video sequence analysis to calculate recovery angles so that the measurement is more accurate and efficient.