% -*- texinfo -*-
% @deftypefn {Function File} {@var{level}=} graythresh (@var{I})
% Compute global image threshold using Otsu's method.
%
% The output @var{level} is a global threshold (level) that can be used to convert
% an intensity image to a binary image with @code{im2bw}.
% @var{level} is a normalized intensity value that lies in the range [0, 1].
%
% The function uses Otsu's method, which chooses the threshold to
% minimize the intraclass variance of the black and white pixels.
%
% Color images are converted grayscale before @var{level} is computed.
% @seealso{im2bw}
% @end deftypefn