A 3D Imaging System for Yarn Hairiness Measurement

Computing & Wireless : Computing Methods

Available for licensing


  • Bugao Xu, Ph.D. , Division of Textiles and Apparel
  • Lei Wang , Division of Textiles and Apparel

Background/unmet need

Yarn hairiness refers to the amount of protruding fibers outside the yarn core, and has a direct effect on weaving production and fabric appearance. The presence of hairy fibers increases the surface friction of yarns and fabrics in the textile process, pilling tendency, and needle and yarn breakage in knitting. Therefore, yarn hairiness is one of the major properties that are routinely inspected in the textile industry.

Hairiness measurements in current photoelectric and imaging methods are based on the projections of fibers onto a 2D plane, ignoring the 3D nature of protruding fibers around the yarn and thus underestimating their true lengths in the space. Researchers at The University of Texas at Austin have developed a novel, accurate, and low-cost yarn hairiness measurement system that is based on a novel 3D imaging method

Invention Description

The 3D yarn hairiness measurement system is a customized microscopic imaging analysis system for automatic and accurate measurements of yarn hairiness. The major components of the system are two mirrors, a microscope, a digital camera, an illuminator, and image analysis software. Multi-views of a yarn from five perspectives are simultaneously created by the two angled mirrors. A visual hull model of a yarn is built by merging the five silhouettes in the directions defined by the scene geometry of the double mirrors. Through the image preprocessing, thresholding, and morphology operations, the yarn core can be located. The dynamic threshold and thinning algorithm are applied to extract the skeletons of protruding fibers. The length and number of fibers on a yarn are then measured from the 3D model, which are highly consistent with the true measurements. A hairiness index can be derived from the amount of the total length of all protruding fibers. The system can be applied to a variety of yarns, such as cotton, cotton-polyester blended, and linen yarns.


  • 3D measurements provide accuracy 
  • Simple and low-cost


  • Uses only one camera and two mirrors to build the visual hull model of a yarn, i.e., a 360° view of the yarn.
  • Compatible with many different types of yarn materials including cotton, cotton-polyester blended, and linen.

Market potential/applications

Textile industry, yarn manufacturers, and testing laboratories.

Development Stage

Lab/bench prototype