A method for determining the proportion of an area covered by a particular type of object. The area is covered by a grid of points and the underlying object identified for each point. The estimate for the proportion of the total area covered by each type of object is then given by: $p_i\approx \frac{h_i}{N}$, where p_i is the true proportion of objects type I, h_i is the number of points in contact with an object type I, and N is the total number of points counted.