Recognizing vehicles under difficult environmental conditions is an enduring challenge to the effective implementation of intelligent transportation systems and autonomous driving technologies. In everyday life, many factors, including poor weather (rain), night-time illumination & darkness, and partial occlusion will greatly reduce the reliability of typical deep learning-based vehicle identifiers. This paper proposes a robust framework for vehicle recognition using 3 complementary strategies: data augmentation; domain adaptation using a Domain- Adversarial Neural Network (DANN); and applying an image enhancement module based on Zero-Reference Deep Curve Estimation (Zero-DCE). The UA-DETRAC dataset was used to develop a robust evaluation protocol based on 5 different scene types: sunny, rainy, night-time, low-light and occluded. At the validation stage, both ResNet50 and EfficientNet-B0 were used as baseline models. Experiments were carried out to compare each of the 3 strategies both separately and in combination. The results showed that using the image enhancement module produced the greatest improvement (8.3% & 7.9%) in coordination with the low-light & night-time scene types respectively. Domain adaptation has improved recognition performance (i.e., the accuracy of recognition) for almost every scene category (particularly those with occlusions), where the use of domain adaptation has increased recognition performance by 6.1%. In addition, combining all three approaches resulted in a very large overall performance increase from an average of 73.4% (baseline) to 87.6%, an improvement of 14.2%. The paper also looks at the time that each method takes to make a prediction and how they can be used together to improve vehicle recognition in applications.
Research Article
Open Access