Script Data for Attribute-Based Recognition of Composite Activities

State-of-the-art human activity recognition methods build on discriminative learning which requires a representative training set for good performance. This leads to scalability issues for the recognition of large sets of highly diverse activities. In this paper we leverage the fact that many human activities are compositional and that the essential components of the activities can be obtained from textual descriptions or scripts. To share and transfer knowledge between composite activities we model them by a common set of attributes corresponding to basic actions and object participants. This attribute representation allows to incorporate script data that delivers new variations of a composite activity or even to unseen composite activities. In our experiments on 41 composite cooking tasks, we found that script data to successfully capture the high variability of composite activities. We show improvements in a supervised case where training data for all composite cooking tasks is available, but we are also able to recognize unseen composites by just using script data and without any manual video annotation.