MATLAB: Add “virtual” background to masked Image

background replacementImage Processing ToolboxmaskingMATLAB

Hey Guys,

I have a question. I wrote a program which extracts the background from an Image (used difference). Then I created the masked Image.

Now I want to add a "virtual" background for example a landscape rgb image (same size as masked one) and place it as a new background for the masked image. So the black background from the masked image should contain/be now the landscape with the foreground of the masked image. It should place the foreground from the masked image at the bottom center of the virtual background

Thank you guys

Best Answer

Try this

rgbImage(maskImage) = backgroundImage(maskImage);

where mask image is the 3-D binary image of the part to be replaced by the background.

Related Solutions

MATLAB: Extract the largest object in the RGB image

OK, if you really need to it work for a full color image, here is code for that:

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 = 22;
%--------------------------------------------------------------------------------------------------------

%    READ IN IMAGE
folder = pwd;
baseFileName = 'image.jpeg';
% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);
% Check if file exists.
if ~exist(fullFileName, 'file')
	% The file doesn't exist -- didn't find it there in that folder.
	% Check the entire search path (other folders) for the file by stripping off the folder.
	fullFileNameOnSearchPath = baseFileName; % No path this time.
	if ~exist(fullFileNameOnSearchPath, 'file')
		% Still didn't find it.  Alert user.
		errorMessage = sprintf('Error: %s does not exist in the search path folders.', fullFileName);
		uiwait(warndlg(errorMessage));
		return;
	end
end
rgbImage = 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(rgbImage);
% Display the image.

hFig = figure;
subplot(2, 2, 1);
imshow(rgbImage, []);
impixelinfo;
title('Original RGB Image', 'FontSize', fontSize, 'Interpreter', 'None');
impixelinfo;
hFig.WindowState = 'maximized'; % May not work in earlier versions of MATLAB.

drawnow;
%--------------------------------------------------------------------------------------------------------
%    EXTRACTION OF IMAGE
% Get the max image
grayImage = min(rgbImage, [], 3);
subplot(2, 2, 2);
imshow(grayImage, []);
impixelinfo;
title('Gray Scale Image', 'FontSize', fontSize, 'Interpreter', 'None');
impixelinfo;
hFig.WindowState = 'maximized'; % May not work in earlier versions of MATLAB.
drawnow;
threshold = 240; % Whatever....
mask = grayImage < threshold; % Create a binary image (a mask)
% Extract the largest blob only.
mask = bwareafilt(mask, 1);
% Fill holes
mask = imfill(mask, 'holes');
% Display the image.
subplot(2, 2, 3);
imshow(mask, []);
title('Mask Image', 'FontSize', fontSize, 'Interpreter', 'None');
axis('on', 'image');
% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);
% Get the mean gray levels in R, G, and B.
meanGLR = mean(rgbImage(redChannel > threshold))
meanGLG = mean(rgbImage(greenChannel > threshold))
meanGLB = mean(rgbImage(blueChannel > threshold))
% Mask the individual color channel images.
% Make outside the mask the mean of what's above the threshold.
redChannel(~mask) = meanGLR;
greenChannel(~mask) = meanGLG;
blueChannel(~mask) = meanGLB;
% Recombine separate color channels into a single, true color RGB image.
rgbImage2 = cat(3, redChannel, greenChannel, blueChannel);
% Display the cropped image.
subplot(2, 2, 4);
imshow(rgbImage2, []);
title('Final Image', 'FontSize', fontSize, 'Interpreter', 'None');
axis('on', 'image');

MATLAB: How to fill the region inside a contour

Alright, 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 long g;
format compact;
fontSize = 20;
%===============================================================================
% Read in good demo image.
folder = pwd;
baseFileName = 'contour.jpg';
% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);
% Check if file exists.
if ~exist(fullFileName, 'file')
  % File doesn't exist -- didn't find it there.  Check the search path for it.
  fullFileNameOnSearchPath = baseFileName; % No path this time.
  if ~exist(fullFileNameOnSearchPath, 'file')
    % Still didn't find it.  Alert user.
    errorMessage = sprintf('Error: %s does not exist in the search path folders.', fullFileName);
    uiwait(warndlg(errorMessage));
    return;
  end
end
rgbImage = imread(fullFileName);
% Get the dimensions of the image.  
% numberOfColorBands should be = 1.
[rows, columns, numberOfColorChannels] = size(rgbImage);
if numberOfColorChannels > 1
  % It's not really gray scale like we expected - it's color.
  % Convert it to gray scale by taking only the green channel.
  grayImage = rgbImage(:, :, 2); % Take green channel.
else
  grayImage = rgbImage; % It's already grayscale.
end
% Display the image.




subplot(2, 3, 1);
imshow(grayImage, []);
axis on;
title('Gray Scale Image', 'FontSize', fontSize, 'Interpreter', 'None');
% 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') 
% Threshold the image
binaryImage = grayImage > 128;
% Display the image.
subplot(2, 3, 2);
imshow(binaryImage, []);
axis on;
title('Binary Image', 'FontSize', fontSize, 'Interpreter', 'None');
% Get rid of huge white surround
binaryImage = imclearborder(binaryImage);
% Display the image.
subplot(2, 3, 3);
imshow(binaryImage, []);
axis on;
title('Border-cleared Binary Image', 'FontSize', fontSize, 'Interpreter', 'None');
% Close the image
se = strel('disk', 2, 0);
binaryImage = imclose(binaryImage, se);
% Display the image.
subplot(2, 3, 4);
imshow(binaryImage, []);
axis on;
title('Closed Image', 'FontSize', fontSize, 'Interpreter', 'None');
% Fill holes
binaryImage = imfill(binaryImage, 'holes');
% Display the image.
subplot(2, 3, 5);
imshow(binaryImage, []);
axis on;
title('Final Image', 'FontSize', fontSize, 'Interpreter', 'None');

Best Answer

Related Solutions

MATLAB: Extract the largest object in the RGB image

MATLAB: How to fill the region inside a contour

Related Question