The main aim of this work ¡s to study of the effect of yarn periodic irregularities on the plain weave fabric appearance using an image analysis method. The pattern of fabric faults was simulated using a prepared computer program. In the experimental stage, two different types of yam were prepared. The first yam was produeed with a certain wavelength and the second yam was prepared with a strong periodic irregularity using an open-end spinning machine. The wavelength of the open-end yarn fault was measured by using an Uster 4 automatic evenness tester. For practical examination, the yams were used as weft in a shuttle loom machine and two types of fabrics were produced. Using image processing, the number and size of the diamond bar pattems, and also the theoretical wavelength of the weft yam, were calculated. The wavelengths calculated theoretically were compared with the actual wavelengths of the weft yams. The results showed an acceptable accuracy of the method.
