% -*- texinfo -*-
% @deftypefn {Function File} {@var{R} =} rangefilt (@var{im})
% @deftypefnx{Function File} {@var{R} =} rangefilt (@var{im}, @var{domain})
% @deftypefnx{Function File} {@var{R} =} rangefilt (@var{im}, @var{domain}, @var{padding}, ...)
% Computes the local intensity range in a neighbourhood around each pixel in
% an image.
%
% The intensity range of the pixels of a neighbourhood is computed as
%
% @example
% @var{R} = max (@var{x}) - min (@var{x})
% @end example
%
% where @var{x} is the value of the pixels in the neighbourhood,
%
% The neighbourhood is defined by the @var{domain} binary mask. Elements of the
% mask with a non-zero value are considered part of the neighbourhood. By default
% a 3 by 3 matrix containing only non-zero values is used.
%
% At the border of the image, extrapolation is used. By default symmetric
% extrapolation is used, but any method supported by the @code{padarray} function
% can be used.
%
% @seealso{paddarray, entropyfilt, stdfilt}
% @end deftypefn