Stop Hiding Behind Windshield: A Windshield Image Enhancer Based on a Two-way Generative Adversarial Network

Windshield images captured by surveillance cameras are usually difficult to be seen through due to severe image degradation such as reflection, motion blur, low light, haze, and noise. Such image degradation hinders the capability of identifying and tracking people. In this paper, we aim to address this challenging windshield images enhancement task by presenting a novel deep learning model based on a two-way generative adversarial network, called Two-way Individual Normalization Perceptual Adversarial Network, TWIN-PAN. TWIN-PAN is an unpaired learning network which does not require pairs of degraded and corresponding ground truth images for training. Also, unlike existing image restoration algorithms which only address one specific type of degradation at once, TWIN-PAN can restore the image from various types of degradation. To restore the content inside the extremely degraded windshield and ensure the semantic consistency of the image, we introduce cyclic perceptual loss to the network and combine it with cycle-consistency loss. Moreover, to generate better restoration images, we introduce individual instance normalization layers for the generators, which can help our generators better adapt to their own input distributions. Furthermore, we collect a large high-quality windshield image dataset (WIE-Dataset) to train our network and to validate the robustness of our method in restoring degraded windshield images. Experimental results on human detection, vehicle ReID and user study manifest that the proposed method is effective for windshield image restoration.