%Aigaion2 BibTeX export from Idiap Publications %Saturday 21 December 2024 01:19:36 AM @INPROCEEDINGS{Tommasi_CLEF2007_2007, author = {Tommasi, Tatiana and Orabona, Francesco and Caputo, Barbara}, projects = {Idiap, EMMA}, title = {CLEF2007 Image Annotation Task: an SVM-based Cue Integration Approach}, booktitle = {Proceedings of ImageCLEF 2007 -LNCS}, year = {2007}, abstract = {This paper presents the algorithms and results of our participation to the medical image annotation task of ImageCLEFmed 2007. We proposed, as a general strategy, a multi-cue approach where images are represented both by global and local descrip- tors, so to capture di{\^{A}}{\textregistered}erent types of information. These cues are combined during the classi{\^{A}}¯cation step following two alternative SVM-based strategies. The {\^{A}}¯rst algorithm, called Discriminative Accumulation Scheme (DAS,',','), trains an SVM for each feature type, and considers as output of each classi{\^{A}}¯er the distance from the separating hyper- plane. The {\^{A}}¯nal decision is taken on a linear combination of these distances: in this way cues are accumulated, thus even when they both are misleaded the {\^{A}}¯nal result can be correct. The second algorithm uses a new Mercer kernel that can accept as input di{\^{A}}{\textregistered}erent feature types while keeping them separated. In this way, cues are selected and weighted, for each class, in a statistically optimal fashion. We call this approach Multi Cue Kernel (MCK). We submitted several runs, testing the performance of the single-cue SVM and of the two cue integration methods. Our team was called BLOOM (BLance{\^{A}}°Or-tOMed.im2) from the name of our sponsors. The DAS algorithm obtained a score of 29.9, which ranked {\^{A}}¯fth among all submissions. We submitted two versions of the MCK algorithm, one using the one-vs-all multiclass extension of SVMs and the other using the one-vs-one extension. They scored respectively 26.85 and 27.54, ranking {\^{A}}¯rst and second among all submissions.}, pdf = {https://publications.idiap.ch/attachments/papers/2008/Tommasi_CLEF2007_2007.pdf} }