Union of an image

Hi Guys

I am new to matlab and I am currently doing a project to distinguish between a photo taken by an amateur photographer and a professional photographer.

How do union or overlap an image over another?

I have to use the combined image to compare with a test image using Scale-Invariant Feature Transform. I sincerely appreciate anyone who is able to help me.

Thanks

Marcus

[Sean de Wolski]

I usually can't tell the difference between amateur and professional photos...

It has more to do with the camera and the fact the professional throws away a high percentage of the shots they take.

[Walter Roberson]

Union or overlap -- is that like "stitching" ?

[Marcus]

Not stitching. Combining two images into one (not side by side and not one on top one at the bottom)

[Jan]

@Walter: I assume he wants an image registration.

Answer 1

[Image Analyst]

Why not just make up your test images in Photoshop or Gimp? Photo-retouching and compositing are what those programs are made for. It's a lot more tedious and less flexible in MATLAB whereas it's interactive and highly visual in Photoshop. You can use masks and feather and anti-alias seams, etc. MATLAB can do it by indexing but it's not very interactive and will have a lot more edge artifacts - it's just not made for that sort of interactive activity.

[Marcus]

Hi

Thanks for the prompt reply. I need it for my project and I am supposed to write a code that does this to process a few thousand images automatically. I just need to overlap/union an image over another. So I cannot use photoshop for this project.

Thanks

Marcus

[Marcus]

Could you provide/suggest a reference code for this? Your help will be greatly appreciated. I am currently using function imadd union images. Will that work?

[Image Analyst]

image2(row1:row2, col1:col2) = imageToPutIn;

works for rectangular images. Was I allowed to give you that code, or would it violate your project rules? It's a lot more complicated for free-form shapes.

[Marcus]

No worries. It wont violate my project. I am just creating a test code to prove some theory for my own use

[Marcus]

can i use image3 = imadd(image1,image2); instead?

[Image Analyst]

If you want to add the values together. With uint8 images the sum will clip at 255. With lower numbers, it will look like the images are averaged or blended together. This does not do a "replacement" of the pixels in one image by pixels in the other image. Plus with imadd, the images have to both be exactly the same size. You can't plop down a small patch from one image onto a larger image.

[Marcus]

The images are of the same size actually.

[Image Analyst]

So try it. Does it do what you want?

[Marcus]

yes but can u provide a reference code with image2(row1:row2, col1:col2) = imageToPutIn; used so I can try it out? Thanks a lot!

[Image Analyst]

If your answer is solved, then go ahead and mark it as such.

clear
clc;
close all;
workspace;  % Make sure the workspace panel is showing.
format longg;
format compact;
fontSize = 20;

% Change the current folder to the folder of this m-file.
if(~isdeployed)
  cd(fileparts(which(mfilename)));
end
  
% Check that user has the Image Processing Toolbox installed.
hasIPT = license('test', 'image_toolbox');
if ~hasIPT
  % User does not have the toolbox installed.
  message = sprintf('Sorry, but you do not seem to have the Image Processing Toolbox.\nDo you want to try to continue anyway?');
  reply = questdlg(message, 'Toolbox missing', 'Yes', 'No', 'Yes');
  if strcmpi(reply, 'No')
    % User said No, so exit.
    return;
  end
end

% Read in a standard MATLAB gray scale demo image.
folder = fullfile(matlabroot, '\toolbox\images\imdemos');
baseFileName = 'Moon.tif';
% 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.
  fullFileName = baseFileName; % No path this time.
  if ~exist(fullFileName, '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
bigGrayImage = imread(fullFileName);
% Get the dimensions of the image.  
% numberOfColorBands should be = 1.
[rows columns numberOfColorBands] = size(bigGrayImage);
% Display the original gray scale image.
subplot(2, 2, 1);
imshow(bigGrayImage, []);
title('Original BIG Grayscale Image', 'FontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
% Give a name to the title bar.
set(gcf,'name','Demo by ImageAnalyst','numbertitle','off') 

% Read in a standard MATLAB gray scale demo image.
folder = fullfile(matlabroot, '\toolbox\images\imdemos');
baseFileName = 'cameraman.tif';
% 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.
  fullFileName = baseFileName; % No path this time.
  if ~exist(fullFileName, '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
smallGrayImage = imread(fullFileName);
% Get the dimensions of the image.  
% numberOfColorBands should be = 1.
[smallRows smallColumns numberOfColorBands] = size(smallGrayImage);
% Display the original gray scale image.
subplot(2, 2, 2);
imshow(smallGrayImage, []);
title('Original SMALL Grayscale Image', 'FontSize', fontSize);
% Note: smallGrayImage could just have well been a sub-portion of
% another image that you extracted out with imcrop() or indexing.

% Paste small image into big one.
% Put upper left at xColumn = 50, and yRow = 100.
xColumn = 50;
yRow = 100;
row1 = yRow;
row2 = row1 + smallRows - 1;
col1 = xColumn;
col2 = col1 + smallColumns - 1;
% Not shown: making sure they don't exceed 
% image boundaries and making adjustments if they do.
pastedImage = bigGrayImage; % Initialize.
pastedImage(row1:row2, col1:col2) = smallGrayImage;
% Display the pasted gray scale image.
subplot(2, 2, 3);
imshow(pastedImage, []);
title('Pasted Image', 'FontSize', fontSize);