An image processing system includes an image sensor that picks up a front-view image in front of an own vehicle. Image processing regions are set to cover on the front-view image, picked up by the image sensor, various portions one after another, which narrow, in area, with different positions in a direction remote from the own vehicle. A feature is extracted out of image processing a portion of the front-view image covered by the image processing regions. The extracted feature is used for vehicle detection.