MatLab - Creating an array of images depending on their correlation - arrays

Question

I've created a program for a project that tests images against one another to see whether or not it's the same image or not. I've decided to use correlation since the images I am using are styled in the same way and with this, I've been able to get everything working up to this point.
I now wish to create an array of images again, but this time, in order of their correlation. So for example, if I'm testing a 50 pence coin and I test 50 images against the 50 pence coin, I want the highest 5 correlations to be stored into an array, which can then be used for later use. But I'm unsure how to do this as each item in the array will need to have more than one variable, which will be the image location/name of the image and it's correlation percentage.
%Program Created By Ben Parry, 2016.
clc(); %Simply clears the console window
%Targets the image the user picks
inputImage = imgetfile();
%Targets all the images inside this directory
referenceFolder = 'M:\Project\MatLab\Coin Image Processing\Saved_Images';
if ~isdir(referenceFolder)
errorMessage = print('Error: Folder does not exist!');
uiwait(warndlg(errorMessage)); %Displays an error if the folder doesn't exist
return;
end
filePattern = fullfile(referenceFolder, '*.jpg');
jpgFiles = dir(filePattern);
for i = 1:length(jpgFiles)
baseFileName = jpgFiles(i).name;
fullFileName = fullfile(referenceFolder, baseFileName);
fprintf(1, 'Reading %s\n', fullFileName);
imageArray = imread(fullFileName);
imshow(imageArray);
firstImage = imread(inputImage); %Reading the image
%Converting the images to Black & White
firstImageBW = im2bw(firstImage);
secondImageBW = im2bw(imageArray);
%Finding the correlation, then coverting it into a percentage
c = corr2(firstImageBW, secondImageBW);
corrValue = sprintf('%.0f%%',100*c);
%Custom messaging for the possible outcomes
corrMatch = sprintf('The images are the same (%s)',corrValue);
corrUnMatch = sprintf('The images are not the same (%s)',corrValue);
%Looping for the possible two outcomes
if c >=0.99 %Define a percentage for the correlation to reach
disp(' ');
disp('Images Tested:');
disp(inputImage);
disp(fullFileName);
disp (corrMatch);
disp(' ');
else
disp(' ');
disp('Images Tested:');
disp(inputImage);
disp(fullFileName);
disp(corrUnMatch);
disp(' ' );
end;
imageArray = imread(fullFileName);
imshow(imageArray);
end

Answer 1

You can use struct() function to create structures.
Initializing an array of struct:
imStruct = struct('fileName', '', 'image', [], 'correlation', 0);
imData = repmat(imStruct, length(jpgFiles), 1);
Setting field values:
for i = 1:length(jpgFiles)
% ...
imData(i).fileName = fullFileName;
imData(i).image = imageArray;
imData(i).correlation = corrValue;
end
Extract values of correlation field and select 5 highest correlations:
corrList = [imData.correlation];
[~, sortedInd] = sort(corrList, 'descend');
selectedData = imData(sortedInd(1:5));