Combine images in matlab with transparency

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Saqib
Saqib on 19 Apr 2014
Commented: Image Analyst on 7 Sep 2014
Hi could anyone among you give me the code on how to combine images
If this is Image(A)
& this is Image(B)
so is it possible to create an image like the one shown below in MATLAB (produced using photoshop) I yes, pease tell me how as i want the appe only to show and the rest to be fully balck or white thanks

Accepted Answer

Image Analyst
Image Analyst on 19 Apr 2014
Try this 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 = 22;
% Read in a standard MATLAB color demo image.
folder = 'C:\Users\saqib\Documents\Temporary';
baseFileName = 'apple.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.
subplot(2, 3, 1);
imshow(rgbImage);
title('Original Color Image', 'FontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
% Extract the individual red, green, and blue color channels.
% redChannel = rgbImage(:, :, 1);
% greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);
% Display the image.
subplot(2, 3, 2);
imshow(blueChannel);
axis on;
title('Blue Image', 'FontSize', fontSize);
% Let's compute and display the histogram.
[pixelCount, grayLevels] = imhist(blueChannel);
subplot(2, 3, 3);
bar(grayLevels, pixelCount);
grid on;
title('Histogram of blue channel', 'FontSize', fontSize);
xlim([0 grayLevels(end)]); % Scale x axis manually.
% Threshold so we can get a binary image to use as a mask.
binaryImage = blueChannel < 100;
% Display the image.
subplot(2, 3, 4);
imshow(binaryImage);
axis on;
title('Binary Image', 'FontSize', fontSize);
% Fill to get rid of holes
binaryImage = imfill(binaryImage, 'holes');
% Get rid of small things
mask = bwareaopen(binaryImage, 1000);
% Display the image.
subplot(2, 3, 5);
imshow(mask);
axis on;
title('Mask Image', 'FontSize', fontSize);
% Mask original image.
% Mask the image using bsxfun() function
maskedRgbImage = bsxfun(@times, rgbImage, cast(mask, class(rgbImage)));
% Display the image.
subplot(2, 3, 6);
imshow(maskedRgbImage);
axis on;
title('Masked Color Image', 'FontSize', fontSize);
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More Answers (3)

Joseph Cheng
Joseph Cheng on 19 Apr 2014
Edited: Joseph Cheng on 19 Apr 2014
If you have the 2nd image (background 0's and apple areas 1) lets call that MASK, and let's call the apple image APPLE.
JustApple = zeros(size(APPLE));
JustApple(MASK) = APPLE(MASK);
if MASK is type logical then above will work. If MASK is not logical and just a matrix of 1s and 0s then JustApple(logical(MASK)) = APPLE(logical(MASK));
  3 Comments
Saqib
Saqib on 20 Apr 2014
thanks & i will use your code oly

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Saqib
Saqib on 19 Apr 2014

Horia
Horia on 10 Aug 2014
Edited: Horia on 7 Sep 2014
#
Suppose:
# A=Name1.bmp;
J = imread(A);
I=rgb2gray(J);
[sz1,sz2]=size(I);
K=zeros(sz1,sz2);
for a=1:2:sz1
for b=1:2:sz2
M=I(a:a+1,b:b+1);
if sum(M(:))>=1000 %I chose white, but you may choose whatever color you want
K(a:a+1,b:b+1)=255;
end
end
end
set(gcf,'Color','None')
# B=Name2.tiff; % (transparent, obtained like Jonas
( <https://stackoverflow.com/questions/13660108/matlab-how-to-save-tiff-with-transparency-or-png-with-no-compression> ) but change "ch" with "K"
#
# Then:
# testbmp=imread('Name1.bmp');
# testtiff=imread(Name2.tiff');
# testbmp(:,:,4)=testtiff(:,:,4);
# imwrite(testbmp,'transparent_fusion.tiff');
  1 Comment
Image Analyst
Image Analyst on 7 Sep 2014
Horia, we have no idea what this is. Please start a new discussion on it and paste the link back here.

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