Recently, an automatic system for grading appearance retention in carpets using our own scanner and image
analysis techniques was proposed. A system for carpets with low pile construction and without color patterns
has been developed. Appearance changes in carpets with high pile construction were still not well detected.
We present an approach based on surface metrology that extract information given by the hairs on the carpet
surface. These features are complementary to the texture features previously explored. By combining both
features, we expand the use of the automatic grading system including some carpets types with high pile
When performing image analysis, one of the most critical steps is the selection of appropriate techniques. A
huge amount of features can be extracted from several techniques and the selection is commonly performed
based on expert knowledge. In this paper we present the theory of experimental designs as a tool for an
objective selection of techniques in image analysis domain. We present a study case for evaluating appearance
retention in textile floor coverings using texture features. The use of experimental design theory permitted to
select an optimal set of techniques for describing the texture changes due to degradation.