Dynamic Orthogonal Projection Constrained Discriminative Tracking

Due to the end-to-end feature learning with convolutional neural networks (CNNs), modern discriminative trackers improve the state of the art significantly. To achieve a strong discrimination, the learned features are usually high-dimensional, resulting in a massive number of parameters contained in the discriminative model and the increase of risk of over-fitting in the online tracking. In this letter, we try to alleviate the risk of over-fitting by means of the adaptive dimensionality reduction (DR) through CNNs. Specifically, an orthogonality constrained ridge regression model is proposed to reduce the dimensionality of features, and a dynamic sub-network (DOPNet) is designed to learn to perform DR. After trained with an orthogonality loss and a regression one, DOPNet generates a set of orthogonal bases (i. e., weights in FC layers) dynamically to reduce the feature dimensionality for a discriminative model in the online tracking. Based on the novel discriminative model and DOPNet, an effective and efficient tracker, DOPTracker, is developed. DOPTracker achieves the state-of-the-art results on four benchmarks, OTB-2015, VOT-2018, NfS, and GOT-10 k while running at 30 FPS.