This paper proposed a real time vehicle speed measurement algorithm based on video image monitoring. According to the speed equation

to get the speed

if we have two images which the acquisition time between them is known

we need to look for a way to get the position of same block in the two images. In this paper

the theory

implementation flowchart and the key points of the algorithm were presented. A fast vehicle lamp locating method based on vehicle lamp characteristic and horizontal gray level difference projection was provided to solve the main difficulty of the algorithm. The experimental result and the problems that could be resolved in the future were discussed in the end

and the block can be located in 13ms meantime on a conventional 800MHz Intel Pentium III. According the data of result in experiment

the accuracy of speed measurement could probably achieve more than 92%. It shows the possibility to offer a real time system to measure speed of vehicle by video only. Because of the simple algorithm

the system can be implemented on a wide range of small low power devices

including embedded processors.