Cam-Net: Compressed Attentive Multi-Granularity Network for Dynamic Scene Classification

Dynamic scene classification on portable platforms is extremely challenging due to the contradiction between model complexity and computing resources. To resolve this long-standing dilemma, we propose the compressed attentive multi-granularity network (CAM-Net) in a two-step manner. First, we present a novel AM-Net based on multi-granularity attention units to boost the performance of the full-precision model. It captures and enhances both coarse and fine target-related information. Then, we introduce an efficient binary approximation to AM-Net to improve computing efficiency, leading to CAM-Net. Particularly, a grouping guidance approach is adopted to guide the reconstruction of full-precision weights from binary ones. With this guidance, CAM-Net can significantly reduce memory usage as well as CPU consumption, yet only cause a slight decline in accuracy. Extensive experiments have been conducted on three benchmark datasets, i.e., Maryland, YUPENN ++ and ActivityNet, demonstrating the effectiveness and superiority of the proposed method on scene classification.