Human facial wrinkles can be effectively utilized for facial analysis. It i
s not an easy task, however, to extract features of wrinkledness directly f
rom a camera image of a human face. For one thing, it is difficult to const
ruct appropriate mathematical models for wrinkle features. In this work, a
fuzzy observer is proposed as a means of providing linguistic descriptions
about the image of a human face with wrinkles. In the proposed observer, so
me well-defined classical image features and numerical information are tran
sformed into fuzzy numbers. A feedforward multilayered artificial neural ne
twork (ANN) is employed for parameter adjustment of the fuzzy observer base
d on the available crisp-input fuzzy-output sample sets. An experiment is p
erformed to demonstrate that the facial wrinkles can be indirectly estimate
d by the proposed fuzzy observer. (C) 2000 Elsevier Science B.V. All rights
reserved.