Deep active learning with Weighting filter for object detection

Active learning has been demonstrated to be effective in reducing labeling costs by selecting the most valuable data from the unlabeled pool. However, the training data of the first epoch in almost all active learning methods is randomly selected, which will cause an instability learning process. Additionally, current active learning, especially uncertainty-based active learning methods, is prone to the problem of data bias because model learning inevitably prefers partial data. For the above issues, we propose Weighting filter (W-filter) tailored for object detection in this paper, which is an image filtering algorithm that can calculate the contribution of a single image to the neural network training as well as remove similar ones in the entire selected data to optimize the sampling results. We first use W-filter to select the training data of the first epoch, which can guarantee better performance and a more stable learning process. Then, we propose to resample the uncertain data from the perspective of the frequency domain to alleviate the problem of data bias. Finally, we redesign several classical uncertainty methods specifically for classification to make them more suitable for the task of object detection. We do rigorous experiments on standard benchmark datasets to validate our work. Several classical detectors such as Faster R-CNN, SSD, R-FCN, CenterNet, EfficientDet, and effective networks including ResNet, DarkNet, MobileNet are used in experiments, which shows our framework is detector-agnostic and network-agnostic and thus can meet any detection scenario.