In a warning apparatus for a vehicle, a primary controller calculates a collision time according to the distance between the vehicle and an object that is present in front of the vehicle and a relative speed between the vehicle and the front object. The protection shields may be configured to protect a headliner assembling containing air ducts and air vents. During a reproduction operation, a two-dimensional photodetector detects the amount of light on per unit pixel block basis to determine the number of its ON pixels and then set a threshold, and thereafter an image pickup device detects the image.