Automatic Detection and Recognition of Thai Vehicle License Plate from CCTV Images

Detection and recognition of Thai vehicle license plates is a challenging area of research. We propose an automatic detection and recognition system for Thai vehicle license plates using CCTV images. For system development, we performed three steps: 1) license plate detection, 2) character segmentation, and 3) character recognition. In step 1, we used YOLOv4 and TensorFlow models as a feature extraction method for Thai license plate detection from CCTV. In this step, we separated data into training and test sets, 3,000 images and 3,000 images, respectively. The dataset had two classes. The test results were with an accuracy of 96.20%. In step 2, we applied OpenCV for character segmentation, and we obtained an accuracy result of 98.40%. In step 3, we used the characters' points of interest for character recognition. In this step, we converted images into text using the Tesseract OCR engine. The results showed that the number recognition could reach an accuracy of 94.20%, while the Thai character recognition has an accuracy of 75.46%.