A Pre-Focusing Method for Detecting Pedestrian Running Out into The Street Using A Mobile Stereo Camera

In mobile stereo camera systems, constructing the 3-D surroundings was one of very important processes for safety navigation, but was very time consuming.  In order to decrease the number of traffic accidental deaths, pedestrians running out into the street should be efficiently detected.   A Pre-Focusing Method (PFM) was proposed for  decreasing the time for getting the matching pixel pairs in the stereo pair images.   The method PFM provided us pre-focused stereo pair images in which an object at the pre-determined distance had no disparity between the images.   The pre-focusing was performed by applying the perspective transformation whose coefficients were obtained by a calibration stage of PFM.  An object at the distance was extracted by evaluating the spatial similarity between pre-focused stereo pair images without scanning to find the matching point pairs.   For avoiding errors due to edge and uniform area, one of the nonparametric tests, the smooth test, was introduced for evaluating the spatial similarity.  A watching window was introduced to detect the pedestrians running out.  The method PFM was successfully applied to an actual video data captured by a stereo video camera mounted on a bicycle.