Abstract: This device can detect an obstacle in a railroad crossing or similar setting by way of image processing independently of a height and a width of an obstacle. The image data read from a video, camera 11 into a multi-valued image memory 13 is compared with background data stored in a background-data creating unit 15 in a data comparator 16. Based on the compared result, a still-object detector 17 detects if an obstacle exists. If it is detected that an obstacle exists and a rod of a crossing gate is down in a gate state detector 18, an alarm output unit 19 serves to output an alarm signal.

Abstract: A vehicle detecting apparatus for detecting a vehicle in each vehicle existence judging region based on binary pixel data, wherein a luminance level at which a variance of luminance of pixels in each vehicle existence judging region takes a maximum value is calculated to thereby perform a vehicle detection by utilizing a change appearing in the variance of luminance in the vehicle existence judging region, where the change is caused by a quite small number of pixels in the vehicle existence judging region having luminance levels lower than a lower threshold value or higher than an upper threshold value, even if the majority of the pixels in the vehicle existence judging region have a luminance close to that of a road surface.