Procedure-Aware Action Quality Assessment: Datasets and Performance Evaluation.

In this paper, we investigate the problem of procedure-aware action quality assessment, which analyzes the action quality by delving into the semantic and spatial-temporal relationships among various composed steps of the action. Most existing action quality assessment methods regress on deep features of entire videos to learn diverse scores, which ignore the relationships among different fine-grained steps in actions and result in limitations in visual interpretability and generalization ability. To address these issues, we construct a fine-grained competitive sports video dataset called FineDiving with detailed semantic and temporal annotations, which helps understand the internal structures of each action. We also propose a new approach (i.e., spatial-temporal segmentation attention, STSA) that introduces procedure segmentation to parse an action into consecutive steps, learns powerful representations from these steps by constructing spatial motion attention and procedure-aware cross-attention, and designs a fine-grained contrastive regression to achieve an interpretable scoring mechanism. In addition, we build a benchmark on the FineDiving dataset to evaluate the performance of representative action quality assessment methods. Then, we expand FineDiving to FineDiving+ and construct three new benchmarks to investigate the transferable abilities between different diving competitions, between synchronized and individual dives, and between springboard and platform dives to demonstrate the generalization abilities of our STSA in unknown scenarios, scoring rules, action types, and difficulty degrees. Extensive experiments demonstrate that our approach, designed for procedure-aware action quality assessment, achieves substantial improvements. Our dataset and code are available at https://github.com/xujinglin/FineDiving. [ABSTRACT FROM AUTHOR]