See my demo:
clc; % Clear the command window.
close all; % Close all figures (except those of imtool.)
imtool close all; % Close all imtool figures if you have the Image Processing Toolbox.
clear; % Erase all existing variables. Or clearvars if you want.
workspace; % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 33;
% Read in a standard MATLAB color demo image.
folder = 'C:\Users\Mark\Documents\Temporary';
baseFileName = 'peppers.png';
% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);
if ~exist(fullFileName, 'file')
% Didn't find it there. Check the search path for it.
fullFileName = baseFileName; % No path this time.
if ~exist(fullFileName, 'file')
% Still didn't find it. Alert user.
errorMessage = sprintf('Error: %s does not exist.', fullFileName);
uiwait(warndlg(errorMessage));
return;
end
end
rgbImage = imread(fullFileName);
% Get the dimensions of the image. numberOfColorBands should be = 3.
[rows, columns, numberOfColorBands] = size(rgbImage);
% Display the original color image.
imshow(rgbImage);
title('Original Color Image', 'FontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
numRectangles = 20;
% Don't allow patches to blow away image and prior patched.
hold on;
for k = 1 : numRectangles
% Get random coordinates.
x1 = columns * rand(1);
x2 = columns * rand(1);
y1 = rows * rand(1);
y2 = rows * rand(1);
% Get random edge color and face colors.
edgeColor = rand(1,3);
faceColor = rand(1,3);
% Display a rectangular solid patch.
patch([x1,x2,x2,x1], [y1,y1,y2,y2], 'r',...
'facecolor', faceColor,...
'edgecolor', edgeColor,...
'facealpha',0.7, ...
'LineWidth', 3)
% See if they want to draw another one.
promptMessage = sprintf('Do you want to Continue processing,\nor Cancel to abort processing?');
titleBarCaption = 'Continue?';
button = questdlg(promptMessage, titleBarCaption, 'Continue', 'Cancel', 'Continue');
if strcmpi(button, 'Cancel')
break;
end
end
