Automatic Number Plate Recognition Using Deep Learning Under Night time and Low-Illumination Conditions

Authors

DOI:

https://doi.org/10.21015/vtse.v14i1.2303

Abstract

Intelligent traffic management relies heavily on the recognition and localization of license plate numbers of moving vehicles, making it a critical task in this field. Numerous methods have been proposed to automate this procedure, utilizing computer vision and image processing algorithms to extract the number and characters from the detected license plate in surveillance photos and videos. However, these methods have primarily focused on daytime photographs and films, neglecting the challenges posed by difficult weather conditions or dim lighting settings. As a result, identifying the position of license plates and interpreting the characters from them remains an understudied area, particularly in low-light environments and night time photography. In response, we present a Night Time number plate detector and recognizer model in this paper. The model begins with a YOLOv5-based detector that has been trained to detect license plates in dark and hazy vehicle photos, generating a polygon bounding box around the number plate. The second phase of the process comprises an improvement module, where the retrieved picture of the license plate undergoes a variety of filters. Lastly, Easy OCR is employed to read the characters on the license plate. Our experimental results demonstrate that training the detector on dark and low illumination photographs, along with precise bounding box generation, significantly improves detection and recognition accuracy. Specifically, our model achieved a mAP score of 97%, highlighting the efficacy of our approach. In conclusion, our Night Time number plate detector and recognizer model represents a significant step forward in the recognition and localization of license plate numbers, particularly in low-light conditions. Our approach provides a powerful and effective tool for intelligent traffic management systems, and we believe that our results will pave the way for further research in this field.

References

Z. Mahmood, K. Khan, U. Khan, S. Adil, S. Ali, and M. Shahzad, "Towards automatic license plate detection," Sensors, vol. 22, no. 3, p. 1245, 2022. doi: 10.3390/s22031245.

X. Zhou, Y. Cheng, L. Jiang, B. Ning, and Y. Wang, "FAFEnet: A fast and accurate model for automatic license plate detection and recognition," IET Image Processing, vol. 17, pp. 807-818, 2023. doi: 10.1049/ipr2.12674.

R. Adak, A. Kumbhar, R. Pathare, and S. Gowda, "Automatic number plate recognition (ANPR) with YOLOv3-CNN," 2022. [Online]. Available: https://arxiv.org/abs/2211.05229.

T. Yuan et al., "Machine learning for intelligent transportation systems," Telecommunication Systems, vol. 33, no. 4, p. e4427, 2022.

M. Humayun, F. Ashfaq, N. Jhanjhi, and M. Alsadun, "Traffic management: Multi-scale vehicle detection in varying weather conditions using YOLOv4 and spatial pyramid pooling network," Electronics, vol. 11, no. 17, p. 2748, 2022. doi: 10.3390/electronics11172748.

M. Humayun, S. Afsar, M. Almufareh, N. Jhanjhi, and M. AlSuwailem, "Smart traffic management system for metropolitan cities of kingdom using cutting edge technologies," Journal of Advanced Transportation, vol. 2022, p. 4687319, 2022.

M. Humayun, M. Almufareh, and N. Jhanjhi, "Autonomous traffic system for emergency vehicles," Electronics, vol. 11, no. 4, p. 510, 2022. doi: 10.3390/electronics11040510.

X. Peng, R. Song, Q. Cao, Y. Li, D. Cui, X. Jia, Z. Lin, and G. Huang, "Real-time illegal parking detection algorithm in urban environments," IEEE Transactions on Intelligent Transportation Systems, vol. 23, pp. 20572-20587, 2022.

Q. Van, H. Van, L. Hoang, T. Ngoc, V. Duc, D. Dai, T. Bao, S. Quang, L. Van, A. Trung, C. Thanh, and H. Manh, "Intelligent parking system using automated license plate recognition and face verification," in Proceedings of International Conference on Computing and Communication Networks, 2022, pp. 219-227.

J. Tang and J. Zeng, "Spatiotemporal gated graph attention network for urban traffic flow prediction based on license plate recognition data," Computer-Aided Civil and Infrastructure Engineering, vol. 37, pp. 3-23, 2022.

A. Luna, C. Trajano, J. So, N. Pascua, A. Magpantay, and S. Ambat, "License plate recognition for stolen vehicles using optical character recognition," in ICT Analysis and Applications, 2022, pp. 575-583.

A. Goyal, D. Agarwal, A. Subramanian, C. Jawahar, R. Sarvadevabhatla, and R. Saluja, "Detecting, tracking and counting motorcycle rider traffic violations on unconstrained roads," in Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, 2022, pp. 4303-4312.

T. Pham, "Effective deep neural networks for license plate detection and recognition," The Visual Computer, vol. 39, pp. 927-941, 2023.

J. Redmon, S. Divvala, R. Girshick, and A. Farhadi, "You only look once: Unified, real-time object detection," in Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, 2016, pp. 779-788.

G. Jocher et al., "ultralytics/yolov5: v6.2 - YOLOv5 classification models, apple m1, reproducibility, clearml and deci.ai integrations," Zenodo, 2022.

S. Raj, Y. Gupta, and R. Malhotra, "License plate recognition system using YOLOv5 and CNN," in 2022 8th International Conference on Advanced Computing and Communication Systems (ICACCS), 2022, vol. 1, pp. 372-377.

Y. Zhao, Y. Shi, and Z. Wang, "The improved YOLOv5 algorithm and its application in small target detection," in International Conference on Intelligent Robotics and Applications, 2022, pp. 679-688.

I. Khan, S. Ali, A. Siddiq, M. Khan, M. Ilyas, S. Alshomrani, and S. Rahardja, "Automatic license plate recognition in real-world traffic videos captured in unconstrained environment by a mobile camera," Electronics, vol. 11, p. 1408, 2022.

P. Batra, I. Hussain, M. Ahad, G. Casalino, M. Alam, A. Khalique, and S. Hassan, "A novel memory and time-efficient ALPR system based on YOLOv5," Sensors, vol. 22, p. 5283, 2022.

Y. Zou, Y. Zhang, J. Yan, X. Jiang, T. Huang, H. Fan, and Z. Cui, "License plate detection and recognition based on YOLOv3 and ILPRNET," Signal, Image and Video Processing, vol. 16, pp. 473-480, 2022.

J. Sang, Z. Wu, P. Guo, H. Hu, H. Xiang, Q. Zhang, and B. Cai, "An improved YOLOv2 for vehicle detection," Sensors, vol. 18, p. 4272, 2018.

L. Zhao and S. Li, "Object detection algorithm based on improved YOLOv3," Electronics, vol. 9, p. 537, 2020.

C. Wang, A. Bochkovskiy, and H. Liao, "Scaled-YOLOv4: Scaling cross stage partial network," in Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, 2021, pp. 13029-13038.

H. Taleb, Z. Li, C. Yuan, H. Wu, X. Zhao, and F. Ghanem, "An effective method for Yemeni license plate recognition based on deep neural networks," in International Conference on Intelligent Computing, 2022, pp. 304-314.

S. Dhonde, J. Mirani, S. Patwardhan, and K. Bhurchandi, "Over-speed and license plate detection of vehicles," in 2022 1st International Conference on the Paradigm Shifts in Communication, Embedded Systems, Machine Learning and Signal Processing (PCEMS), 2022, pp. 113-118.

Q. Zhu, Y. Liu, Z. Zhao, and X. Ma, "Research on license plate location algorithm based on YOLOv5," Journal of Physics: Conference Series, vol. 2278, p. 012040, 2022.

R. Chen et al., "Automatic license plate recognition via sliding-window Darknet-YOLO deep learning," Image and Vision Computing, vol. 87, pp. 47-56, 2019.

S. Park, S. Yu, J. Kim, and H. Yoon, "An all-in-one vehicle type and license plate recognition system using YOLOv4," Sensors, vol. 22, p. 921, 2022.

H. Padmasiri, J. Shashirangana, D. Meedeniya, O. Rana, and C. Perera, "Automated license plate recognition for resource-constrained environments," Sensors, vol. 22, p. 1434, 2022.

I. Shafi, I. Hussain, J. Ahmad, P. Kim, G. Choi, I. Ashraf, and S. Din, "License plate identification and recognition in a non-standard environment using neural pattern matching," Complex & Intelligent Systems, vol. 8, pp. 3627-3639, 2022.

M. Asif, C. Qi, T. Wang, M. Fareed, and S. Raza, "License plate detection for multi-national vehicles: An illumination invariant approach in multi-lane environment," Computers & Electrical Engineering, vol. 78, pp. 132-147, 2019.

S. Yoo and M. Han, "Temporal matching prior network for vehicle license plate detection and recognition in videos," ETRI Journal, vol. 42, pp. 411-419, 2020.

A. Baral, A. Koirala, S. Pantha, R. Pokhrel, and B. Paudel, "Automatic license plate recognition for distorted images using SRGAN," in High Performance Computing and Networking: Select Proceedings of CHSN 2021, 2022, pp. 121-131.

V. Kukreja, D. Kumar, A. Kaur et al., "GAN-based synthetic data augmentation for increased CNN performance in vehicle number plate recognition," in 2020 4th International Conference on Electronics, Communication and Aerospace Technology (ICECA), 2020, pp. 1190-1195.

H. Ibrahim, O. Fahmy, and M. Elattar, "License plate image analysis empowered by generative adversarial neural networks (GANs)," IEEE Access, vol. 10, pp. 30846-30857, 2022.

M. Meng, C. He, and X. Qi, "An incomplete license plate image intelligent recognition system based on the generated counter network," in IoT and Big Data Technologies for Health Care, 2021, pp. 570-582.

I. Shah, N. Jhanjhi, and A. Laraib, "Cybersecurity and blockchain usage in contemporary business," in Handbook of Research on Cybersecurity Issues and Challenges for Business and FinTech Applications, 2023, pp. 49-64.

"Ultralytics YOLOv5," GitHub. [Online]. Available: https://github.com/ultralytics/yolov5. Accessed: Mar. 27, 2026.

G. Bradski, "The OpenCV library," Dr. Dobb's Journal, 2000.

"Open source data labeling platform," Label Studio. [Online]. Available: https://labelstud.io/. Accessed: Jan. 30, 2023.

L. Gaur and N. Jhanjhi, Digital Twins and Healthcare: Trends, Techniques, and Challenges. Hershey, PA, USA: IGI Global, 2022.

D. Alferidah and N. Jhanjhi, "Cybersecurity impact over big-data and IoT growth," in 2020 International Conference on Computational Intelligence (ICCI), 2020, pp. 103-108.

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Published

2026-03-25

How to Cite

Ashfaq, F., Jhanjhi, N. Z., M. Ahmed, H., & Koondhar , M. Y. (2026). Automatic Number Plate Recognition Using Deep Learning Under Night time and Low-Illumination Conditions. VFAST Transactions on Software Engineering, 14(1), 240–252. https://doi.org/10.21015/vtse.v14i1.2303