Pictures and video sequences showing human faces are of high importance in
content-based retrieval systems, and consequently face detection has been e
stablished as an important tool in the framework of many multimedia applica
tions like indexing, scene classification and news summarisation, In this w
ork, we combine skin colour and shape features with template matching in an
efficient way for the purpose of facial image indexing. We propose an adap
tive two-dimensional Gaussian model of the skin colour distribution whose p
arameters are re-estimated based oil the current image or frame, reducing g
eneralisation problems, Masked areas obtained from skin colour detection ar
e processed using morphological tools and assessed using global shape featu
res. The verification stage is based on a template matching variation provi
ding robust detection. Facial images and video sequences are indexed accord
ing to the number of included faces, their average colour components and th
eir scale. leading to new types of content-based retrieval criteria in quer
y-by-example frameworks. Experimental results have shown that the proposed
implementation combines efficiency, robustness and speed, and could be easi
ly embedded in generic visual information retrieval systems or video databa
ses.