LIGHT DISTRIBUTION CONTROLLING DEVICE, VEHICLE POSITION DETECTING DEVICE, VEHICLE LAMP SYSTEM, LIGHT DISTRIBUTION CONTROLLING METHOD, AND VEHICLE POSITION DETECTING METHOD

A light distribution controlling device includes a vehicle detector that detects a front vehicle through an image analysis on an image obtained from an imaging device, a region determiner that sets a processing region by adding a margin in a widthwise direction of the vehicle to a presence region of the front vehicle, and a pattern determiner that, in parallel with the detection of the front vehicle, sets a light blocking portion based on a pixel value of a pair of luminous points included in the processing region in the image and determines a light distribution pattern that includes the light blocking portion.