function J = amedfilt2(I)
% 2-D Adaptive Median Filter
% This filter ignores edge effects and boundary conditions, as such, the
% output is a cropped version of the original image, where the amount
% cropped is equal to the maximum window size vertically and horizontally.

% Define smax as a constant
smax = 9;

% Initialize Output Image (J)
J = I;

% Calculate valid region limits for filter
[nrows ncols] = size(I);
ll = ceil(smax/2);
ul = floor(smax/2);

% Loop over the entire image ignoring edge effects
for rows = ll:nrows-ul
    for cols = ll:ncols-ul
        for s = 3:2:smax

            % grab block region
            window_ind = -floor(s/2):floor(s/2);
            region = I(rows+window_ind,cols+window_ind);

            % calculate rmin, rmax, rmed
            rmin = min(region(:));
            rmax = max(region(:));
            rmed = median(region(:));

            % current sweet spot pixel value
            centerpixel = region(ceil(s/2),ceil(s/2));
            
            % adapt region size
            if rmed > rmin && rmed < rmax
                if centerpixel <= rmin || centerpixel >= rmax
                    J(rows,cols) = rmed;
                end

                % stop adapting
                break;
            end

            
        end
    end
end