PT Unknown AU David Aldavert Ricardo Toledo Arnau Ramisa Ramon Lopez de Mantaras TI Efficient Object Pixel-Level Categorization using Bag of Features: Advances in Visual Computing BT 5th International Symposium on Visual Computing PY 2009 BP 44–55 VL 5875 DI 10.1007/978-3-642-10331-5_5 AB In this paper we present a pixel-level object categorization method suitable to be applied under real-time constraints. Since pixels are categorized using a bag of features scheme, the major bottleneck of such an approach would be the feature pooling in local histograms of visual words. Therefore, we propose to bypass this time-consuming step and directly obtain the score from a linear Support Vector Machine classifier. This is achieved by creating an integral image of the components of the SVM which can readily obtain the classification score for any image sub-window with only 10 additions and 2 products, regardless of its size. Besides, we evaluated the performance of two efficient feature quantization methods: the Hierarchical K-Means and the Extremely Randomized Forest. All experiments have been done in the Graz02 database, showing comparable, or even better results to related work with a lower computational cost. ER