Try this:
% Demo by Image Analyst
clc; % Clear the command window.
close all; % Close all figures (except those of imtool.)
clear; % Erase all existing variables. Or clearvars if you want.
workspace; % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 20;
markerSize = 40;
%--------------------------------------------------------------------------------------------------------
% READ IN IMAGE
fileName = 'image.png';
grayImage = imread(fileName);
% Get the dimensions of the image.
% numberOfColorChannels should be = 1 for a gray scale image, and 3 for an RGB color image.
[rows, columns, numberOfColorChannels] = size(grayImage)
if numberOfColorChannels > 1
% It's not really gray scale like we expected - it's color.
% Extract the red channel (so the magenta lines will be white).
grayImage = grayImage(:, :, 1);
end
%--------------------------------------------------------------------------------------------------------
% Display the image.
subplot(2, 2, 1);
imshow(grayImage, []);
impixelinfo;
axis('on', 'image');
title('Original Gray Scale Image', 'FontSize', fontSize, 'Interpreter', 'None');
hold on
drawnow;
% Maximize window.
g = gcf;
g.WindowState = 'maximized'
drawnow;
% Get a mask:
binaryImage = grayImage < 128;
% Display the image.
subplot(2, 2, 2);
imshow(binaryImage, []);
impixelinfo;
axis('on', 'image');
title('Mask/Binary/Logical Image', 'FontSize', fontSize, 'Interpreter', 'None');
hold on
drawnow;
% Label each blob with 8-connectivity, so we can make measurements of it
[labeledImage, numberOfBlobs] = bwlabel(binaryImage, 8);
% Display the image.
subplot(2, 2, 3);
imshow(labeledImage, []);
impixelinfo;
axis('on', 'image');
title('Labeled Image', 'FontSize', fontSize, 'Interpreter', 'None');
hold on
drawnow;
% Apply a variety of pseudo-colors to the regions.
coloredLabelsImage = label2rgb (labeledImage, 'jet', [0,0,.5]);
% Display the pseudo-colored image.
subplot(2, 2, 4);
imshow(coloredLabelsImage);
impixelinfo;
axis('on', 'image');
title('Colorized Labeled Image', 'FontSize', fontSize, 'Interpreter', 'None');
hold on
drawnow;
[EDIT] Just a note to say that while this may look pretty, it's not very useful because you cannot tell if nearby blobs are connected because their colors are so similar. You'd be better off with shuffling the colors like this:
coloredLabelsImage = label2rgb (labeledImage, 'jet', 'k', 'shuffle');
