On the Uncertainty of Straight Lines in Digital Images

A model for the uncertainty of straight lines extracted from digital images is proposed, which accounts both for the image discretization and for the scattering of the line points from the true line. First, some results about uncertainty are derived for the discrete model, in which the point scattering is neglected. Then, the proposed model is compared with the continuous model, in which the image discretization is neglected: experiments show that the continuous model underestimates uncertainty.