A correct programme to determine the exact interior of any discrete closed planar curve
In order to fill up interiors, drawing programmes usually resort to polynomial approximation. This leads to occasional flaws that are normally hidden by smoothing procedures. For instance, in Mathematical Morphology the grayscale dilation can smoke a picture and so cover up the sparse pixel flaws. However, for a binary environment this trick can harm the original contour. Herewith we present an exact filling procedure that works out for any discrete closed curve.