In the video detection system of urban traffic flow
it is a hard work to detect vehicle at night. The traditional methods are based on vehicle headlights and headlight beams using mathematical morphology
they are sensitive to environment illumination with high computing cost. This paper presents a method based on color and motion information. Firstly
the algorithm detects and tracks vehicle taillights using color information on the images
then matches the detected vehicle taillights using motion information and priori knowledge
finally vehicle flow is computed. As shown in experiments
the algorithm can exactly detect moving vehicles at night and it is robust to rainy conditions.