Patent ID: 6961476

Claim:
A method of determining an optimal threshold value (t o ) for an image, said method comprising the steps of: a) obtaining an image; b) selecting a test segment of said image; c) determining the mean feature size (S) of features appearing in said test segment of said image at each of a plurality of threshold values (t), so as to produce mean feature size data (S(t)); d) selecting a subset of the mean feature size data gathered in step c); and e) determining an optimal threshold value (t o ) as a function of said subset of mean feature size data; wherein the step of selecting includes the steps of: f) counting the number of features (N) appearing in said test segment of said image at each of a plurality of threshold values (t), so as to produce counting data (N(t)); h) determining a cutoff threshold value (t c ) as a function of said counting data (N(t)); and i) selecting a subset of the mean feature size data (S(t)) as a function of the cutoff threshold value (t c ).