A fully automatic method for pilling evaluation in wear-and-tear fabri
cs is developed from the image analysis of a set of standard photograp
hs (Zweigle KG-741 Reutlingen). The method involves operations in both
the spatial and frequency domains to segment pills from the textured
background of the web. It calculates the total area of pilling in the
sample image and assigns a degree of pilling according to the standard
. Two mathematical descriptions are analyzed according to the underlyi
ng rule established by the standard images, using the visual estimatio
n of the area of pilling performed by a group of observers. A logarith
mic (in base two) approach, which is consistent with human visual perc
eption laws and facilitates an optimization of the method, is eventual
ly adopted. (C) 1998 Society of Photo-Optical Instrumentation Engineer
s. [S0091-3286(98)02111-4].