add binarize method

Author: dlegland

src/@Image/binarize.m

@@ -0,0 +1,43 @@
+function bin = binarize(obj, varargin)
+% Binarize a grayscale or intensity image.
+%
+%   BIN = binarize(IMG)
+%   Converts the grayscale or intensity image IMG into a binary image by
+%   applying threshold.
+%
+%   BIN = binarize(IMG, T)
+%   Converts to a binary image by explicitely specifying the threshold
+%   value. Result is equivalent to IMG > T.
+%
+%
+%   Example
+%     img = Image.read('coins.png');
+%     bin = binarize(img);
+%     show(bin)
+%
+%   See also
+%     componentLabeling, otsuThreshold, maxEntropyThreshold
+%
+ 
+% ------
+% Author: David Legland
+% e-mail: david.legland@inrae.fr
+% INRAE - BIA Research Unit - BIBS Platform (Nantes)
+% Created: 2020-11-18,    using Matlab 9.8.0.1323502 (R2020a)
+% Copyright 2020 INRAE.
+
+if isempty(varargin)
+    bin = otsuThreshold(obj);
+else
+    var1 = varargin{1};
+    if isnumeric(var1)
+        bin = img > value;
+    else
+        error('Unknown option');
+    end
+end
+
+% setup result image name
+if ~isempty(obj.Name)
+    bin.Name = sprintf('binarize(%s)', obj.Name);
+end

src/@Image/componentLabeling.m

@@ -43,3 +43,8 @@
 res = Image('Data', data, ...
     'Parent', obj, ...
     'Type', 'label');
+
+% setup result image name
+if ~isempty(obj.Name)
+    res.Name = sprintf('componentLabeling(%s)', obj.Name);
+end

src/@Image/fold.m

@@ -7,11 +7,11 @@
 %   the number of rows in the array (N).
 %
 %   Example
-%     % Read color image, and convert to N-by-P data array
+%     % Read color image, and convert to N-by-P Table class
 %     img = Image.read('peppers.png');
-%     data = double(unfold(img));
+%     tab = unfold(img);
 %     % Performs basic clustering
-%     km = kmeans(data, 6);
+%     km = kmeans(tab, 6);
 %     % Convert result to imaeg using the 'fold' method
 %     img2 = Image.fold(km+1, size(img), 'type', 'label', 'Name', 'km3 labels');
 %     figure; show(label2rgb(img2, 'jet'));

src/@Image/label2rgb.m

@@ -2,14 +2,19 @@
 % Convert label image to RGB image.
 %
 %   RGB = label2rgb(LBL)
-%   Covnerts the label image LBL to a RGB image. The result image is
+%   Converts the label image LBL to a RGB image. The result image is
 %   encoded into uint8.
 %
 %   Example
-%     label2rgb
+%     img = Image.read('coins.png');
+%     bin = closing(img > 80, ones(3,3));
+%     lbl = componentLabeling(bin);
+%     rgb = label2rgb(lbl, 'jet', 'w', 'shuffle');
+%     rgb.Name = 'regions(coins)';
+%     figure; show(rgb);
 %
 %   See also
-%     watershed
+%     watershed, binarize
 %
 
 % ------
@@ -58,4 +63,9 @@
 end
 
 % create new image
-rgb = Image('data', data, 'parent', obj, 'type', 'color');
+rgb = Image('Data', data, 'Parent', obj, 'Type', 'Color');
+
+% setup result image name
+if ~isempty(obj.Name)
+    rgb.Name = sprintf('label2rgb(%s)', obj.Name);
+end

src/@Image/maxEntropyThreshold.m

@@ -14,7 +14,7 @@
 %
 %
 %   See also
-%     otsuThreshold, maxEntropyThresholdValue
+%     binarize, otsuThreshold, maxEntropyThresholdValue
 %
 
 % ------

src/@Image/otsuThreshold.m

@@ -25,7 +25,7 @@
 %
 %
 %   See also
-%     histogram, otsuThresholdValue, maxEntropyThreshold, lt, le
+%     binarize, otsuThresholdValue, maxEntropyThreshold, lt, le, histogram
 %
 
 % ------

tests/image/test_binarize.m

@@ -0,0 +1,30 @@
+function tests = test_binarize
+% Test suite for the file binarize.
+%
+%   Test suite for the file binarize
+%
+%   Example
+%   test_binarize
+%
+%   See also
+%     binarize
+
+% ------
+% Author: David Legland
+% e-mail: david.legland@inrae.fr
+% Created: 2020-11-18,    using Matlab 9.8.0.1323502 (R2020a)
+% Copyright 2020 INRAE - BIA-BIBS.
+
+tests = functiontests(localfunctions);
+
+function test_Simple(testCase) %#ok<*DEFNU>
+% Test call of function without argument.
+
+data = magic(5);
+img = Image(data);
+
+bin = binarize(img);
+
+assertTrue(testCase, isa(bin, 'Image'));
+assertTrue(testCase, isBinaryImage(bin));
+