Papers by Keyword: License Plate Location

Abstract: The license plate recognition system is an important part of modern traffic management. application which is very extensive. In this paper, a method to achieve three main modules split from the image pre-processing, license plate location and character. Image pre-processing module of this article is to image gray and step by Roberts operator edge detection. License plate positioning and segmentation using mathematical morphology is used to determine the license plate location method, and then use the license plate color information of color segmentation method to complete the license plate parts division. This article is to research its main part and use MATLAB to do the image processing simulation.

Abstract: According to restrictions existing in the application of single license plate location algorithm in complicated background. A license plate location algorithm based on mathematical morphology and color characteristics is proposed. Firstly, the new method uses Ostu algorithm to select an optimal threshold, and according to the threshold carries on binary processing, then by using a new method of mathematical morphology for image edge detection. Finally combined mathematical morphology with color characteristic to locate license plate .Experiments show that this new method with higher accuracy and fewer restrictions on background is superior to traditional or a single method and can be widely used.

Abstract: A vehicle plate location algorithm under complex scenes is presented that based on interest region extraction and morphology. First of all, extract the edge of the lane, obtain the driveway area from the edge of the road, confirm the region of interest with the experiences in the driveway area, it can reduce the scope for searching. Then preprocessing is used in the vehicle image, including gray, edge detection and binary transformation is used. Then a series of morphological operations are used to look for candidate regions that probably contain the characters in range of sizes. Finally, the vehicle license plate can be found according to the median filter.

Abstract: License plate location (LPL) plays an important role in license plate (LP) recognition systems. Most existing methods can only deal with LPL well in fixed environment such as stable illumination, simple background or constant distance between cameras and vehicles. And the successful rate of LPL is quite affected by those non-LP objects in the background that share similar features with license plate regions. To overcome these problems, in this paper, we propose a novel LPL method using perceptual salient features, which is based on the visual attention mechanism to choose the most salient features for license plate. The proposed approach consists of two main steps. Firstly, candidate license plate regions consistent with the visual perception are detected based on perceptual salient features from the saliency map. Then, the candidate license plate regions are sifted to distinguish a license plate from background, using salient features which are selected and organized by minimizing probability of error. The proposed algorithm was tested with 1942 real images captured in various conditions and achieved an average accuracy of 98.51%. The experiment result shows that our algorithm is robust to the interference of non-LP objects as well as the change of illumination, view angle, position, size and color of license plates.

Abstract: License plate location is the first and crucial stage in license plate recognition. Although many license plate location methods achieve higher success rate, they are always time-consuming. However, robust real-time characteristic is important to application of license plate recognition. In this paper, a texture-based method of license plate location is proposed to enhance real-time characteristic while keeping higher success rate. It consists of three parts: preprocessing, region of interested (ROI) location and ROI filtration. Experimental has demonstrated that the proposed method achieve average execution time of 49ms and success rate of 96.3% simultaneously.

Abstract: Since it is difficult to locate license plate quickly and precisely under complicated background and different illumination conditions, therefore, this paper proposes a high-speed and precise approach to solve such kind of problem on the basis of texture analysis and projection method. The approach utilizes both rich textural feature and projective statistical feature of characters in LP region to carry out coarse and fine license plate location. The experiment shows that, under different illumination, car models and background conditions, such approach is proved to be fast, precise and practical.

Abstract: The license plate recognition(LPR) is the key technology in intelligent transportation system. This paper discusses the whole process of license plate recognition technology, include the license plate image preprocessing, license plate location, character segmentation and character recognition, and simulated it by MATLAB. The experimental result show this method can obtain good recognition effect.

Abstract: With the development and progress of the economic and technology, transportation has become more and more important in human’s usual life. Intelligent transportation system can be used in many areas. Images in RGB color space are very sensitive to the environment light intensity, and what’s more, there may be some pollution appeared on the plate and so on, these made it difficult to locate the plate area. In this paper, we proposed some new algorithms. In the first stage, car image preprocess, a new algorithm named color division was proposed. Experiments show that, influences from the environment as well as some inevitably differences of colors in the plate into standard color, so the performance of whole system was improved. In the period of license location, a new algorithm based on license color pairs was proposed, and it has good performance after experiments.

Abstract: The license plate location method is the key technology of license plate recognition system, new algorithm is proposed based on LOG operator detecting edge of License Plate Location. First, a large number of color plate images are preprocessed to remove the background interference information, and then rough location of license plate based on block method, search area of plate will be greatly reduced and accurate positioning the plate will be realized by LOG operator combined with projection method. Static license plate image positioning by simulation and analysis show that the method has high accuracy in license plate location.

Abstract: In the Automatic License Plate Recognition (ALPR) system, the License Plate Location (LPL) is the key step before the final recognition. This paper proposed an improved LPL algorithm for Vietnam vehicle license plates (LP). The proposed algorithm consists of three main modules: Pre-processing (convert RGB image to grayscale image, adjust grayscale image intensity, image binarization use Otsu method), LP candidates location (morphology opening to remove noises & dilation operation, measure properties of image regions to find candidates), LP exactly location (finding the LP angle & rotating LP, cut exactly LP region). We implemented test for 350 Vietnam vehicle images, which obtained from the actual system, the average rate of accuracy of our method is 98.64%, our results are more exactly presented methods.