Measurement of yarn hairiness by digital image processing

Abstract

In their effort to measure yarn hairiness at high speed, the commercially available yarn hairiness testers resort to indirect techniques. Measurement of true length of all hairs can only be done by observing the yarn under a microscope and obtaining a trace of hairs. An attempt was made in this work to automate this task using digital image processing. The challenges were two-fold. The first was development of an algorithm capable of analysing yarn images taken under varying lighting conditions and varying yarn positions. The second was determination of minimum requirement of the image-capturing instrument. Both of these have been reported in this work. A new hairiness index has been proposed and suggested as a better indicator of hairiness than the traditional definition.

Keywords:

• hairiness
• digital image
• edge detection
• microscope
• camera

Acknowledgements

The authors are grateful to the Bombay Textile Research Association for allowing some of the experiments reported in this work to be conducted in their laboratory.