| dc.description.abstract | As the growing and progressive of technology, people change the styles of daily life, especially on the land vehicle. When people pursued advanced techniques as well as the humanistic technology, the traffic safety is also an important issue.
We integrate the front car detection in day and night time, using different algorithm for the different time. The beginning we defined a criterion for judging what it day or night is, and decided what the algorithm we choose. The criterion judging day or night, we fetch fixed number of frame from different video. We fetch fixed pixels at fixed position for representing the whole image which size is 320×240, then calculating the average intensity and the percentage of bellow the threshold of pixels we fetch. According to the criterion, judging what it day or night is.
In daytime forwarding collision warning system, we fetch vertical edge response image and horizontal edge response image by second difference mask. For adapting different weather, we filter the background at the upper half of the image according to the result of lane detection system before defining threshold. Then we generate the bi-level gradient image with appropriate threshold. Then find the continuous pixels belong to the horizontal edge, the horizontal edge we divided into positive and negative for representing the bottom of car and body of car respectively. We find whether it has enough of vertical edge patency or symmetric vertical edge pair at the end point of horizontal edge. If the horizontal edge confirmed, we calculate the proportion of width of the horizontal edge with lane with. If the proportion confirmed, the candidate vehicles generate.
In nighttime forward collision warning system, we detect the tails of preceding vehicles. Then, we pair the lights using the features of the horizontal distance, the vertical heights, the trajectory, and correlation of a pair of lights. Finally, we estimate the time to collision (TTC) of the verified light pair and providing the warning for the driver.
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