+ImgProc/adaptiveThresh.m
function imBW = adaptiveThresh(im, sigma)
%% Adaptive threshold an image using Gaussian filter with a given stdv.

%% License
% ACADEMIC OR NON-PROFIT ORGANIZATION NONCOMMERCIAL RESEARCH USE ONLY
% Copyright (c) 2018 Bingyao Huang
% All rights reserved.

% Redistribution and use in source and binary forms, with or without
% modification, are permitted provided that the following conditions are met:

% The above copyright notice and this permission notice shall be included in all
% copies or substantial portions of the Software.

% If you publish results obtained using this software, please cite our paper.

% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
% SOFTWARE.

%%

if(nargin < 2)
    sigma = 0.5;
end

imSize = size(im);

% convert to gray scale image
if(numel(imSize)>2 && imSize(3) == 3)
    imGray = rgb2gray(im);
else
    imGray = im;
end

imGaussianMean = imgaussfilt(imGray, sigma);
imBW = imGray > imGaussianMean;
end