1. A method of normalizing brightness in an image, comprising: receiving an image made up of areas, each area having an original brightness value; dividing the image up into blocks of areas; determining an estimated brightness of each block; determining an brightness distribution value for each area by fitting the estimated brightness determined for each block surrounding the area using bilinear interpolation and extrapolation; normalizing a brightness value for each area by dividing an original brightness value for the area by the brightness distribution value determined for the area to produce a normalized brightness value; and creating a new image using the normalized brightness value for each area.