Semantic Decomposition and Recognition of Long and Complex Manipulation Action Sequences
This addresses the challenge of understanding continuous human actions in computer vision, which is important for applications like robotics and surveillance, though it appears incremental as it builds on the existing SEC concept.
The paper tackles the problem of recognizing long and complex manipulation actions, such as 'preparing a breakfast', by introducing a method based on Semantic Event Chains (SEC) that captures spatiotemporal interactions between objects and hands, achieving robust performance validated on various datasets.
Understanding continuous human actions is a non-trivial but important problem in computer vision. Although there exists a large corpus of work in the recognition of action sequences, most approaches suffer from problems relating to vast variations in motions, action combinations, and scene contexts. In this paper, we introduce a novel method for semantic segmentation and recognition of long and complex manipulation action tasks, such as "preparing a breakfast" or "making a sandwich". We represent manipulations with our recently introduced "Semantic Event Chain" (SEC) concept, which captures the underlying spatiotemporal structure of an action invariant to motion, velocity, and scene context. Solely based on the spatiotemporal interactions between manipulated objects and hands in the extracted SEC, the framework automatically parses individual manipulation streams performed either sequentially or concurrently. Using event chains, our method further extracts basic primitive elements of each parsed manipulation. Without requiring any prior object knowledge, the proposed framework can also extract object-like scene entities that exhibit the same role in semantically similar manipulations. We conduct extensive experiments on various recent datasets to validate the robustness of the framework.