Documents relevant to the subject of image indexing and retrieval, obtained
from the SCI and SSCI databases, were examined and analyzed. The study con
firms that there exist in this rapidly growing field two distinctive resear
ch groups employing the content-based and description-based approaches, res
pectively. However, research in the content-based domain is currently domin
ating in the field, while the other approach has less visibility. Although
researchers using the content-based approach actively communicated with col
leagues from the same group, collaboration between the different clusters o
f scientists should be further promoted and encouraged to advance research
and development in image indexing and retrieval.