| Popis: |
We propose LASER, a neuro-symbolic approach to learn semantic video representations that capture rich spatial and temporal properties in video data by leveraging high-level logic specifications. In particular, we formulate the problem in terms of alignment between raw videos and spatio-temporal logic specifications. The alignment algorithm leverages a differentiable symbolic reasoner and a combination of contrastive, temporal, and semantics losses. It effectively and efficiently trains low-level perception models to extract a fine-grained video representation in the form of a spatio-temporal scene graph that conforms to the desired high-level specification. To practically reduce the manual effort of obtaining ground truth labels, we derive logic specifications from captions by employing a large language model with a generic prompting template. In doing so, we explore a novel methodology that weakly supervises the learning of spatio-temporal scene graphs with widely accessible video-caption data. We evaluate our method on three datasets with rich spatial and temporal specifications: 20BN-Something-Something, MUGEN, and OpenPVSG. We demonstrate that our method learns better fine-grained video semantics than existing baselines. |
