%Aigaion2 BibTeX export from Idiap Publications %Thursday 21 November 2024 11:32:30 AM @TECHREPORT{Tommasi_Idiap-RR-77-2008, author = {Tommasi, Tatiana and Orabona, Francesco and Caputo, Barbara}, projects = {Idiap, EMMA}, month = {12}, title = {CLEF2008 Image Annotation Task: an SVM Confidence-Based Approach}, type = {Idiap-RR}, number = {Idiap-RR-77-2008}, year = {2008}, institution = {Idiap}, note = {CLEF 2008 Working Notes}, abstract = {This paper presents the algorithms and results of our participation to the medi- cal image annotation task of ImageCLEFmed 2008. Our previous experience in the same task in 2007 suggests that combining multiple cues with di{\"{\i}}¬€erent SVM-based approaches is very e{\"{\i}}¬€ective in this domain. Moreover it points out that local features are the most discriminative cues for the problem at hand. On these basis we decided to integrate two di{\"{\i}}¬€erent local structural and textural descriptors. Cues are combined through simple concatenation of the feature vectors and through the Multi-Cue Ker- nel. The trickiest part of the challenge this year was annotating images coming mainly from classes with only few examples in the training set. We tackled the problem on two fronts: (1) we introduced a further integration strategy using SVM as an opinion maker. It consists in combining the {\"{\i}}¬rst two opinions on the basis of a technique to evaluate the con{\"{\i}}¬dence of the classi{\"{\i}}¬er{\^{a}}€™s decisions. This approach produces class labels with {\^{a}}€{\oe}don{\^{a}}€™t know{\^{a}}€ wildcards opportunely placed; (2) we enriched the poorly populated training classes adding virtual examples generated slightly modifying the original images. We submitted several runs considering di{\"{\i}}¬€erent combination of the proposed techniques. Our team was called {\^{a}}€{\oe}idiap{\^{a}}€. The run using jointly the low cue- integration technique, the con{\"{\i}}¬dence-based opinion fusion and the virtual examples, scored 74.92 ranking {\"{\i}}¬rst among all submissions.}, pdf = {https://publications.idiap.ch/attachments/reports/2008/Tommasi_Idiap-RR-77-2008.pdf} }