The University of Surrey Visual Concept Detection System at ImageCLEF 2010: Working Notes

Visual concept detection is one of the most important tasks in image and video indexing. This paper describes our system in the ImageCLEF Visual Concept Detection Task 2010 which ranked first for large-scale visual concept detection tasks in terms of Equal Error Rate (EER) and Area under Curve (AUC) and ranked third in terms of ontology measure. The presented approach involves state-of-the-art local descriptor computation, vector quantisation via clustering, structured scene or object representation via localised histograms of vector codes, similarity measure for kernel construction and classifier learning. The main novelty is the classifierlevel and kernel-level fusion using Kernel Discriminant Analysis with RBF/Power Chi-Squared kernels obtained from various image descriptors. For 32 out of 53 individual concepts, we obtain the best performance of all 12 submissions to this task.