Edge detection of license plate based on wavelet transform and quantum genetic algorithm

摘要

Edge detection is one of the most commonly used operations in image analysis of license plate. The classical edge detection algorithm based on wavelet transform utilizes a threshold to remove noise from license plate image, and then detects edge with wavelet transform. In the condition with strong noise, the classical edge detection algorithm often works not well enough. The proposed edge detection algorithm combines the wavelet transform and quantum genetic algorithm and significantly improves the result. Specifically, wavelet decomposition is applied to get a set of low and high frequency sub-images from image of license plate and quantum genetic algorithm is applied to optimize wavelet denoising threshold which removing the noise of the high-frequency sub-images, finally the edge image is obtained by reconstructing the high-frequency sub-images without noise. The efficiency of the method is better than the classical one and is proved by computer simulation.