Strategies for fast license plate number localization

Though several effective image processing algorithms are created nowadays, their application is often limited by huge computation requirements, making real time operation impossible. Generally speaking, algorithms of only higher complexity can provide better and more accurate solutions, but these require significantly more computational time and powerful resources. Procedures based on any kind of segmenting are complicated and diverse, a special example for this is license plate number recognition. Two major issues can be distinguished in license plate number identification, i.e. the localization of the number plate in the picture and the recognition of characters within the identified area, where the country specific signs and registration number types must also be handled. Neither of the tasks mentioned is easy, requiring considerable processing time, but some measurements indicate that finding and extracting characters often takes 20-25 times longer than recognizing them. The localization strategies introduced in the following are intended to reduce this difference.