XRCE's Participation to ImageCLEFphoto 2007
Stéphane Clinchant, Jean-Michel Renders, Gabriela Csurka · 2007
Our participation to ImageCLEFphoto07, for the first time, was motivated by assessing several transmedia similarity measures that we recently designed and developed. The object of investigation consists here in some “intermediate level ” fusion approaches, where we use some principles coming from pseudo-relevance feedback and, more specifically, use transmedia pseudo-relevance feedback for enriching the mono-media representation of an object with features coming from the other media. One issue that arises when adopting such a strategy is to determine how to compute the mono-media similarity between an aggregate of objects coming from a first (pseudo-)feedback step and one single multimodal object. We propose two alternative ways of adressing this issue, that result in what we called the “transmedia document reranking ” and “complementary feedback ” methods respectively. This year, with a “lightly ” annotated corpus of images, it appears that mono-media retrieval performance is more or less equivalent for pure image and pure text content (around 20 % MAP). Using our transmedia pseudofeedback-based similarity measures