Abstract

The popular bag-of-words paradigm for action recognition tasks is based on building histograms of quantized features, typically at the cost of discarding all information about relationships between them. However, although the beneficial nature of including these relationships seems obvious, in practice finding good representations for feature rela- tionships in video is difficult. We propose a simple and computationally efficient method for expressing pairwise relationships between quantized features that combines the power of discriminative representations with key aspects of Na¨?ve Bayes. We demonstrate how our technique can aug- ment both appearance- and motion-based features, and that it signifi- cantly improves performance on both types of features.