Fisher Kernels on Visual Vocabularies for Image Categorization

作者：Florent Perronnin, Christopher R. Dance · 年份：2007 · DOI：10.1109/cvpr.2007.383266 · 被引用次数：1655 · 研究领域：Advanced Image and Video Retrieval Techniques、Image Retrieval and Classification Techniques、Remote-Sensing Image Classification

Within the field of pattern classification, the Fisher kernel is a powerful framework which combines the strengths of generative and discriminative approaches. The idea is to characterize a signal with a gradient vector derived from a generative probability model and to subsequently feed this representation to a discriminative classifier. We propose to apply this framework to image categorization where the input signals are images and where the underlying generative model is a visual vocabulary: a Gaussian mixture model which approximates the distribution of low-level features in images. We show that Fisher kernels can actually be understood as an extension of the popular bag-of-visterms. Our approach demonstrates excellent performance on two challenging databases: an in-house database of 19 object/scene categories and the recently released VOC 2006 database. It is also very practical: it has low computational needs both at training and test time and vocabularies trained on one set of categories can be applied to another set without any significant loss in performance.