Content-based image retrieval methods based on the Euclidean metric expect
the feature space to be isotropic. They suffer from unequal differential re
levance of features in computing the similarity between images in the input
feature space. We propose a learning method that attempts to overcome this
limitation by capturing local differential relevance of features based on
user feedback. This feedback, in the form of accept or reject examples gene
rated in response to a query image, is used to locally estimate the strengt
h of features along each dimension while taking into consideration the corr
elation between features. This results in local neighborhoods that are cons
tricted along feature dimensions and that are most relevant, while elongate
d along less relevant ones. In addition to exploring and exploiting local p
rincipal information, the system seeks a global space for efficient indepen
dent feature analysis by combining such local information. We provide exper
imental results that demonstrate the efficacy of our technique using both s
imulated and real-world data. (C) 2001 Elsevier Science B.V. All rights res
erved.