LIRIS-Imagine at ImageCLEF 2012 Photo Annotation Task

In this paper, we present the methods we have proposed and evaluated through the ImageCLEF 2012 Photo Annotation task. More precisely, we have proposed the Histogram of Textual Concepts (HTC) textual feature to capture the relatedness of semantic concepts. In contrast to term frequency-based text representations mostly used for visual concept detection and annotation, HTC relies on the semantic similarity between the user tags and a concept dictionary. Moreover, a Selective Weighted Late Fusion (SWLF) is introduced to combine multiple sources of information which by iteratively selecting and weighting the best features for each concept at hand to be classified. The results have shown that the combination of our HTC feature with visual features through SWLF can improve the performance significantly. Our best model, which is a late fusion of textual and visual features, achieved a MiAP (Mean interpolated Average Precision) of 43.67% and ranked first out of the 80 submitted runs.