Visual Phrases for automatic images annotation

Visual characteristics of objects of a class vary with the considered instance and the shooting conditions. In this paper we proposed a visual characterization of object parts, called "Visual Phrase", robust to these variations. A Visual Phrase is a set of regions of interest built according to predefined criteria; a topological criterion was studied in this paper. An automatic annotation method is proposed based on our definition and characterization of Visual Phrases. Experiments on VOC2009 collection is presented, we show that the late fusion of our method with a standard Bag of Visual Words approach on full images provides better results than those obtained via each approach independently.