Learning intra-inter semantic aggregation for video object detection

Video object detection is a challenging task due to the appearance deterioration problems in video frames. Thus, object features extracted from different frames of a video are usually deteriorated in varying degrees. Currently, some state-of-the-art methods enhance the deteriorated object features in a reference frame by aggregating the undeteriorated object features extracted from other frames, simply based on their learned appearance relation among object features. In this paper, we propose a novel intra-inter semantic aggregation method (ISA) to learn more effective intra and inter relations for semantically aggregating object features. Specifically, in the proposed ISA, we first introduce an intra semantic aggregation module (Intra-SAM) to enhance the deteriorated spatial features based on the learned intra relation among the features at different positions of an individual object. Then, we present an inter semantic aggregation module (Inter-SAM) to enhance the deteriorated object features in the temporal domain based on the learned inter relation among object features. As a result, by leveraging Intra-SAM and Inter-SAM, the proposed ISA can generate discriminative features from the novel perspective of intra-inter semantic aggregation for robust video object detection. We conduct extensive experiments on the ImageNet VID dataset to evaluate ISA. The proposed ISA obtains 84.5% mAP and 85.2% mAP with ResNet-101 and ResNeXt-101, and it achieves superior performance compared with several state-of-the-art video object detectors.