The Enhancement for Foggy Traffic Image Based on EM Algorithm

In bad weather, such as foggy, the vision become poor, and this often induce many problems for traffic safety. So it is a hot research subject how to improve the vision ability for bad weather in traffic, and there are many achievements have been made. Among these the single scale Retinex algorithm is a common used method, which was proposed by Land. According this theory, any obtained image can be divided into two images: illumination image and object reflected image. If the illumination can be estimated accurately, the high quality enhanced image (reflected image) will be obtained easily. In this paper, one efficient method (EFTI-EM) for illumination was proposed, which is used to estimate the illumination by using sky area in a foggy traffic image and to get sky area is based on EM algorithm. By setting a considerable number of tests, satisfactory results have been achieved.