I think the Squire et al. papers from 1999 accessible from the Viper site in Geneva cite a paper of Tversky's which justifies asymmetric similarity matrices: What you are looking for influences your notion of similarity. Cheers, Wolfgang
On Thu, Apr 16, 2009 at 8:14 AM, Henning Müller < [email protected]> wrote: > Dear Juan, > > this is normal as the similarity measure of GIFT is not a metric as it is > based on a tf/idf weighting form text retrieval. > Image similarity is calculated in the space spanned by the features present > in the query, only. Each image has around 1500 features out of 87000 > possible (most of them binary features), so each image potentially spans a > different sub-space in which similarity is calculated. > > Cheers, Henning > > Juan C. Caicedo a écrit : > >> Hello everybody, >> >> We are building a similarity matrix of an image collection using GIFT. >> However, we notice that this matrix is not a symmetric one. >> Could anybody tells us what is the reason of this behaviour and some hints >> to obtain a symmetric similarity matrix? >> >> Thanks in advance to all you. >> >> Juan C. Caicedo >> >> >> ------------------------------------------------------------------------ >> >> _______________________________________________ >> help-GIFT mailing list >> [email protected] >> http://lists.gnu.org/mailman/listinfo/help-gift >> > > > > _______________________________________________ > help-GIFT mailing list > [email protected] > http://lists.gnu.org/mailman/listinfo/help-gift >
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