METHOD FOR DETECTING DEFECTS ON YARNS

摘要

In a first aspect, the present invention provides a method for detecting defects on yarns arranged substantially in parallel from a grey scale image (10) of the yarns, said grey scale image being divided into one or more image sections; the method comprising for each image section (10): calculating a restrictive threshold and a less restrictive threshold from the image section (10); obtaining a restrictive image section (11) by applying the restrictive threshold to the image section (10); obtaining a less restrictive image section (12) by applying the less restrictive threshold to the image section (10). Said method further comprises: obtaining a differential image (13) from the obtained restrictive image sections (11) and the obtained less restrictive image sections (12); and detecting defects on the yarns by comparing (15) the pixels (16) of the differential image (13) representing existence of difference with predetermined defect patterns (14).