Patent ID: 8180108

Claim:
A method for determining a distance of visibility for a driver of a vehicle in the presence of a disruptive element disrupting the visibility of the driver, comprising the following steps: videoing at least one image of a field of space located in front of the vehicle, said at least one image being defined by an array of pixels and sweep-lines; separating said at least one image in two parts by a first line passing through a pre-set point; determining a luminosity of pixels of said first line; determining a curve of luminosity using said luminosity of said pixels in said first line; determining a first tangent to said curve of luminosity tangential at a place of said curve representative of a region of luminosity substantially independent of the disruptive element; determining a second tangent to said curve of luminosity tangential at a place of said curve representative of stabilization of the luminosity; determining a sweep-line according to the first tangent and second tangent; and determining the distance of visibility using said sweep-line; wherein said sweep line is determined using at least one intersection point between said curve of luminosity and a line generally parallel to said first tangent at a given distance from said first tangent and said second tangent.