A vehicle surroundings monitoring apparatus that extracts a body present
in the surroundings of a vehicle as an object, based on an image captured
by an infrared imaging device, includes: a binarized object extraction
device that extracts a binarized object from image data obtained by
binarizing a gray scale images of the image; a search region setting
device that sets a search region including a bottom end of the binarized
object extracted by the binarized object extraction device, on the gray
scale image; a horizontal edge detection device that detects a horizontal
edge in the search region; a horizontal edge width calculation device
that calculates a width of the horizontal edge or a status quantity
related to the width; and an object type determination device that
determines a type of the object based on the width of the horizontal edge
or the status quantity related to the width.