Abstract
Accuracy and real-timeliness are the top concerns in vehicle plate recognition. Several factors put restrictions on plate recognition system, including illumination, vehicle high speed, camera angle, and bad weather condition. Damaged and pale plates also lead to incorrect recognition in the present approaches. In this regard, this paper proposes an efficient robust method for vehicle plate recognition, which consists of four steps: (i) vehicle detection, (ii) plate detection, (iii) character segmentation, and (iv) character recognition. In the first step, the vehicle image is detected using background emission. Plates are localized by means of character recognition and pattern matching approaches in the second step, where the contours are recognized and extracted using connected component analysis, and then, low-density areas are emitted using density criterion and vehicle plate is extracted. In the third step, statistical feature, filtering methods, and morphology operators are employed for segmentation and extraction of plate characters. After plate segmentation, statistical and global features and local pattern are extracted from each segment image for segment classification in the final step, where features are ranked using F-Score, and then, classification of each section to one of 37 classes is performed using random forest. The proposed method is evaluated using several databases in both left to right and right to left languages; English for the former and Persian for the latter. In the first part of the evaluation, the proposed approach is evaluated in terms of robustness and recognition speed. The proposed method has the accuracy of 99.2% for plate recognition, 100% for plate segmentation, and 98.41% for character recognition. In this part, the dataset of Iranian plates is collected by the authors of this paper. However, character recognition rate is 100% in other Persian databases. Moreover, the experimental evaluations witness that the proposed method can process at least 8 frames per second, that means it is fast enough to be adopted for real-time applications. In the second phase, the proposed method is evaluated on an English plate dataset. In this dataset, the proposed method shows an accuracy of 100% for plate detection and 97.5% for character recognition. The experimental results show that the proposed method outperforms methods proposed in recent years in terms of time and accuracy that is also independent of plate language.
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References
Zhang, L., Wang, P., Li, H., Li, Z., Shen, C., Zhang, Y.: A robust attentional framework for license plate recognition in the wild (2020). arXiv:2006.03919
Panahi, R., Gholampour, I.: Accurate detection and recognition of dirty vehicle plate numbers for high-speed applications. IEEE Trans. Intell. Transport. Syst. 18(4), 767–779 (2016)
Huang, Q., Cai, Z., Lan, T.: A new approach for character recognition of multi-style vehicle license plates. In: IEEE Transactions on Multimedia (2020)
Al-Ghaili, A.M., Mashohor, S., Ramli, A.R., Ismail, A.: Vertical-edge-based car-license-plate detection method. IEEE Trans. Veh. Technol. 62(1), 26–38 (2012)
Mousa, A.: Canny edge-detection based vehicle plate recognition. Int. J. Signal Process. Image Process. Pattern Recogn. 5(3), 1–8 (2012)
Sanyuan, Z., Mingli, Z., Xiuzi, Y.: Car plate character extraction under complicated environment. In: 2004 IEEE International Conference on Systems, Man and Cybernetics (IEEE Cat. No. 04CH37583), vol. 5, pp. 4722–4726. IEEE (2004)
Deb, K., Vavilin, A., Jo, K.-H.: An efficient method for correcting vehicle license plate tilt. In: 2010 IEEE International Conference on Granular Computing, pp. 127–132. IEEE (2010)
Kanani, P., Gupta, A., Yadav, D., Bodade, R., Pachori, R.B.: Vehicle license plate localization using wavelets. In: 2013 IEEE Conference on Information & Communication Technologies, pp. 1160–1164. IEEE (2013)
Lee, R.T., Hung, K.-C.: Real-time vehicle license plate recognition based on 1-d discrete periodic wavelet transform. In: International Symposium on Computer. Consumer and Control, vol. 2012, pp. 914–917. IEEE (2012)
Arafat, M.Y., Khairuddin, A.S.M., Paramesran, R.: Connected component analysis integrated edge based technique for automatic vehicular license plate recognition framework. In: IET Intelligent Transport Systems (2020)
Deb, K., Gubarev, V.V., Jo, K.-H.: Vehicle license plate detection algorithm based on color space and geometrical properties. In: International Conference on Intelligent Computing, pp. 555–564. Springer (2009)
Deb, K., Lim, H., Kang, S.-J., Jo, K.-H.: An efficient method of vehicle license plate detection based on hsi color model and histogram. In: International Conference on Industrial, Engineering and Other Applications of Applied Intelligent Systems, pp. 66–75. Springer (2009)
Lee , E.R., Kim, P.K., Kim H.J.: Automatic recognition of a car license plate using color image processing. In: Proceedings of 1st International Conference on Image Processing, vol. 2, pp. 301–305. IEEE (1994)
Azad, R., Davami, F., Azad, B.: A novel and robust method for automatic license plate recognition system based on pattern recognition. Adv. Comput. Sci. 2(3), 64–70 (2013)
Wang, Y.-R., Lin, W.-H., Horng, S.-J.: A sliding window technique for efficient license plate localization based on discrete wavelet transform. Expert Syst. Appl. 38(4), 3142–3146 (2011)
Yu, S., Li, B., Zhang, Q., Liu, C., Meng, M.Q.-H.: A novel license plate location method based on wavelet transform and emd analysis. Pattern Recogn. 48(1), 114–125 (2015)
Sarfraz, M.S., Shahzad, A., Elahi, M.A., Fraz, M., Zafar, I., Edirisinghe, E.A.: Real-time automatic license plate recognition for cctv forensic applications. J. Real-Time Image Proc. 8(3), 285–295 (2013)
Llorens, D., Marzal, A., Palazón, V., Vilar, J.M.: Car license plates extraction and recognition based on connected components analysis and hmm decoding. In: Iberian Conference on Pattern Recognition and Image Analysis, pp. 571–578. Springer (2005)
Al-Shemarry, M.S., Li, Y., Abdulla, S.: Ensemble of adaboost cascades of 3l-lbps classifiers for license plates detection with low quality images. Expert Syst. Appl. 92, 216–235 (2018)
Safaei, A., Tang, H.L., Sanei, S.: Real-time search-free multiple license plate recognition via likelihood estimation of saliency. Comput. Electr. Eng. 56, 15–29 (2016)
Dollár, P., Tu, Z., Perona, P., Belongie, S.: Integral channel features (2009)
Yang, B., Yan, J., Lei, Z., Li, S.Z.: Aggregate channel features for multi-view face detection. In: IEEE International Joint Conference on Biometrics, pp. 1–8. IEEE (2014)
Fischler, M.A., Bolles, R.C.: Random sample consensus: a paradigm for model fitting with applications to image analysis and automated cartography. Commun. ACM 24(6), 381–395 (1981)
Horn, B.K., Schunck, B.G.: Determining optical flow. In: Techniques and Applications of Image Understanding, vol. 281, pp. 319–331. International Society for Optics and Photonics (1981)
Lucas, B.D., Kanade, T., et al.: An iterative image registration technique with an application to stereo vision (1981)
McCane, B., Novins, K., Crannitch, D., Galvin, B.: On benchmarking optical flow. Comput. Vis. Image Underst. 84(1), 126–143 (2001)
Everingham, M., Eslami, S.A., Van Gool, L., Williams, C.K., Winn, J., Zisserman, A.: The pascal visual object classes challenge: a retrospective. Int. J. Comput. Vis. 111(1), 98–136 (2015)
Turchenko, V., Kochan, V., Koval, V., Sachenko, A., Markowsky, G.: Smart vehicle screening system using artificial intelligence methods. In: Proceedings of 2003 Spring IEEE Conference on Technologies for Homeland Security, pp. 182–185 (2003)
Li, H., Shen, C.: Reading car license plates using deep convolutional neural networks and lstms (2016). arXiv:1601.05610
Rasheed, S., Naeem, A., Ishaq, O.: Automated number plate recognition using hough lines and template matching. In: Proceedings of the World Congress on Engineering and Computer Science, vol. 1, pp. 24–26 (2012)
Ghofrani, S., Rasooli, M.: Farsi license plate detection and recognition based on characters features (2011)
Girshick, R., Donahue, J., Darrell, T., Malik, J.: Rich feature hierarchies for accurate object detection and semantic segmentation. In: Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, pp. 580–587 (2014)
Dehshibi, M.M., Allahverdi, R.: Persian vehicle license plate recognition using multiclass adaboost. Int. J. Comput. Electr. Eng. 4(3), 355 (2012)
Lowe, D.G.: Distinctive image features from scale-invariant keypoints. Int. J. Comput. Vis. 60(2), 91–110 (2004)
Bay, H., Tuytelaars, T., Van Gool, L.: Surf: Speeded up robust features. In: European Conference on Computer Vision, pp. 404–417. Springer (2006)
Björklund, T., Fiandrotti, A., Annarumma, M., Francini, G., Magli, E.: Automatic license plate recognition with convolutional neural networks trained on synthetic data. In: IEEE 19th International Workshop on Multimedia Signal Processing (MMSP), vol. 2017, pp. 1–6. IEEE (2017)
Gao, F., Cai, Y., Ge, Y., Lu, S.: Edf-lpr: a new encoder-decoder framework for license plate recognition. IET Intell. Transport. Syst. 14(8), 959–969 (2020)
Rizvi, S.T.H., Patti, D., Björklund, T., Cabodi, G., Francini, G.: Deep classifiers-based license plate detection, localization and recognition on gpu-powered mobile platform. Future Internet 9(4), 66 (2017)
Nejati, M., Majidi, A., Jalalat, M.: License plate recognition based on edge histogram analysis and classifier ensemble. In: Signal Processing and Intelligent Systems Conference (SPIS), vol. 2015, pp. 48–52. IEEE (2015)
Izidio, D.M., Ferreira, A.P., Medeiros, H.R., Barros, E.N.D.S.: An embedded automatic license plate recognition system using deep learning. In: Design Automation for Embedded Systems, pp. 1–21 (2019)
Gao, P., Zeng, Z., Sun, S.: Segmentation-free vehicle license plate recognition using cnn. In: International Conference on Signal and Information Processing, Networking and Computers, pp. 50–57. Springer (2018)
Li, H., Wang, P., Shen, C.: Toward end-to-end car license plate detection and recognition with deep neural networks. IEEE Trans. Intell. Transp. Syst. 20(3), 1126–1136 (2018)
Wang, W., Yang, J., Chen, M., Wang, P.: A light cnn for end-to-end car license plates detection and recognition. In: IEEE Access, vol. 7, pp. 173875–173883 (2019)
Omar, N., Sengur, A., Al-Ali, S.G.S.: Cascaded deep learning-based efficient approach for license plate detection and recognition. Expert Syst. Appl. 149, 113280 (2020)
LeCun, Y.: Mnist dataset (2013). http://yann.lecun.com/exdb/mnist/
Jiao, J., Ye, Q., Huang, Q.: A configurable method for multi-style license plate recognition. Pattern Recogn. 42(3), 358–369 (2009)
Slobodan Ribaric, T.H., Kalafati, Z.: Vehicle plate dataset (2015). http://www.zemris.fer.hr/projects/LicensePlates/english/
Wen, Y., Lu, Y., Yan, J., Zhou, Z., von Deneen, K.M., Shi, P.: An algorithm for license plate recognition applied to intelligent transportation system. IEEE Trans. Intell. Transp. Syst. 12(3), 830–845 (2011)
Chen, Z.-X., Liu, C.-Y., Chang, F.-L., Wang, G.-Y.: Automatic license-plate location and recognition based on feature salience. IEEE Trans. Veh. Technol. 58(7), 3781–3785 (2009)
Guo, J.-M., Liu, Y.-F.: License plate localization and character segmentation with feedback self-learning and hybrid binarization techniques. IEEE Trans. Veh. Technol. 57(3), 1417–1424 (2008)
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Pirgazi, J., Sorkhi, A.G. & Kallehbasti, M.M.P. An efficient robust method for accurate and real-time vehicle plate recognition. J Real-Time Image Proc 18, 1759–1772 (2021). https://doi.org/10.1007/s11554-021-01118-7
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DOI: https://doi.org/10.1007/s11554-021-01118-7