MATLAB: Editing Images In Matlab

editImage Processing Toolboximages

Hi all

I was wondering if there was any way of editing an image in Matlab.

My aim is to import an image (.jpg) and based on certain criteria automatically draw a Red box in the middle of th eimage and fill the box with red color and then adjust the transparancey so that you can still see the contents of the image.

Below is an example of what i hope to achieve:-

Does anyone have any ideas?

Thank you.

Best Answer

Just add an offset to the red channel in the zone you want

rgbImage = imread(filename);
rgbImage(row1:row2, col1:col2, 1) = rgbImage(row1:row2, col1:col2, 1) + 50; % Make red channel 50 gray levels brighter.

Related Solutions

MATLAB: Binary Image – Black region detection

Mohsina, try this:

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 short g;
format compact;
fontSize = 25;
%===============================================================================

% Get the name of the image the user wants to use.
baseFileName = 'image1.png';
% Get the full filename, with path prepended.
folder = []; % Determine where demo folder is (works with all versions).
fullFileName = fullfile(folder, baseFileName);
%===============================================================================
% Read in a demo image.
grayImage = imread(fullFileName);
% 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.
  % Use weighted sum of ALL channels to create a gray scale image.
  grayImage = rgb2gray(grayImage);
  % ALTERNATE METHOD: Convert it to gray scale by taking only the green channel,
  % which in a typical snapshot will be the least noisy channel.
  % grayImage = grayImage(:, :, 2); % Take green channel.
end
% Display the image.



subplot(2, 2, 1);
imshow(grayImage, []);
axis on;
axis image;
caption = sprintf('Original Gray Scale Image');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo();
% Set up figure properties:
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0, 0, 1, 1]);
% Get rid of tool bar and pulldown menus that are along top of figure.
% set(gcf, 'Toolbar', 'none', 'Menu', 'none');
% Give a name to the title bar.
set(gcf, 'Name', 'Demo by ImageAnalyst', 'NumberTitle', 'Off')
drawnow;
% Create binary image of the black blobs from grayscale image.
binaryImage = grayImage == 0;
% Get rid of the background.
binaryImage = imclearborder(binaryImage);
% Display the image.
subplot(2, 2, 2);
imshow(binaryImage, []);
axis on;
axis image;
title('Binary Image', 'FontSize', fontSize, 'Interpreter', 'None');
% Label the blobs
[labeledImage, numBlobs] = bwlabel(binaryImage);
% Display the image.
subplot(2, 2, 2);
imshow(binaryImage, []);
axis on;
axis image;
title('Binary Image', 'FontSize', fontSize, 'Interpreter', 'None');
% Let's assign each blob a different color to visually show the user the distinct blobs.
coloredLabels = label2rgb (labeledImage, 'hsv', 'k', 'shuffle'); % pseudo random color labels
% coloredLabels is an RGB image.  We could have applied a colormap instead (but only with R2014b and later)
subplot(2, 2, 3);
imshow(coloredLabels);
axis on;
axis image; % Make sure image is not artificially stretched because of screen's aspect ratio.
caption = sprintf('Pseudo colored labels, from label2rgb().');
title(caption, 'FontSize', fontSize);
drawnow;
% Make measurements of bounding box.
props = regionprops(labeledImage, 'BoundingBox');
% Display the image.
subplot(2, 2, 4);
imshow(binaryImage, []);
axis on;
axis image;
title('Binary Image with Boxes', 'FontSize', fontSize, 'Interpreter', 'None');
% Display the bounding boxes around them.
hold on;
for k = 1 : numBlobs
  thisBoundingBox = props(k).BoundingBox
  rectangle('Position', thisBoundingBox, ...
    'EdgeColor', 'c', 'LineWidth', 2);
end

MATLAB: Extracting black pixels from a specific region of an image and overlaying it on another image

Here's the full demo for you:

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 short g;
format compact;
fontSize = 25;
%===============================================================================


% Get the name of the image the user wants to use.
baseFileName = 'o4s1_11.bmp';
% Get the full filename, with path prepended.
folder = pwd
fullFileName = fullfile(folder, baseFileName);
%===============================================================================
% Read in a first image.
grayImage1 = imread(fullFileName);
% 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(grayImage1)
if numberOfColorChannels > 1
  % It's not really gray scale like we expected - it's color.

  % Use weighted sum of ALL channels to create a gray scale image.

%   grayImage = rgb2gray(grayImage);

  % ALTERNATE METHOD: Convert it to gray scale by taking only the green channel,

  % which in a typical snapshot will be the least noisy channel.

  grayImage1 = grayImage1(:, :, 2); % Take green channel.

end
% Display the image.



subplot(2, 2, 1);
imshow(grayImage1, []);
axis on;
axis image;
caption = sprintf('Image1');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo();
% Set up figure properties:
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0, 0.04, 1, .96]);
% Get rid of tool bar and pulldown menus that are along top of figure.
% set(gcf, 'Toolbar', 'none', 'Menu', 'none');
% Give a name to the title bar.
set(gcf, 'Name', 'Demo by ImageAnalyst', 'NumberTitle', 'Off')
drawnow;
%===============================================================================
% Read in a second image.
fullFileName = fullfile(pwd, 'blankv5.bmp');
grayImage2 = imread(fullFileName);
% 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(grayImage2)
if numberOfColorChannels > 1
  % It's not really gray scale like we expected - it's color.
  % Use weighted sum of ALL channels to create a gray scale image.
%   grayImage = rgb2gray(grayImage);
  % ALTERNATE METHOD: Convert it to gray scale by taking only the green channel,
  % which in a typical snapshot will be the least noisy channel.
  grayImage2 = grayImage2(:, :, 2); % Take green channel.
end
% Display the image.
subplot(2, 2, 2);
imshow(grayImage2, []);
axis on;
axis image;
caption = sprintf('Image2');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo();
% Display the histogram of the image so we can see what threshold to use.
subplot(2, 2, 3);
histogram(grayImage2);
grid on;
% Binarize the image.
threshold = 128;
binaryImage = grayImage1 < threshold;  % Determine number from histogram.
% Get rid of surround that is touching the border.
binaryImage = imclearborder(binaryImage);
% Display the image.
subplot(2, 2, 3);
imshow(binaryImage, []);
axis on;
axis image;
caption = sprintf('Binary Image');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo();
% Use this binary image to transfer the stuff in the second image.
grayImage2(binaryImage) = grayImage1(binaryImage);
% Display the image.
subplot(2, 2, 4);
imshow(grayImage2, []);
axis on;
axis image;
caption = sprintf('Final Image');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;

Best Answer

Related Solutions

MATLAB: Binary Image – Black region detection

MATLAB: Extracting black pixels from a specific region of an image and overlaying it on another image

Related Question