HT extracted feature parameter values for the real data over 100 random samplings at 10, 50 and 100% data density.

θaverage and θmedian are the mean and median values of the orientation angle of all the lines for a particular sampling. Daverage and Dmedian are the mean and median values of the diameter of all the circles. μ and σ are respectively the mean and standard deviation over the 100 random samplings for the average and the median values of the θ and D distributions.