helperFillMissingViews.m

function filledImageFiles = helperFillMissingViews(imageFiles)
  
    % Extract all unique view identifiers from all cameras.
    allViewIdentifiers = [];
    for i = 1:numel(imageFiles)
        % Extract view identifiers from filenames.
        viewIdentifiers = helperExtractViewIdentifiers(imageFiles{i});
        allViewIdentifiers = union(allViewIdentifiers,viewIdentifiers);
    end
      
    % Initialize the filled image files cell array.
    filledImageFiles = cell(size(imageFiles));
      
    % Fill missing views with empty strings.
    for i = 1:numel(imageFiles)
        % Extract view identifiers for the current camera.
        currentFiles = imageFiles{i};
        currentViewIdentifiers = helperExtractViewIdentifiers(currentFiles);
          
        % Initialize a cell array to store aligned filenames.
        filledFiles = strings(numel(allViewIdentifiers),1);
          
        % Match views using identifiers and fill missing entries with empty strings.
        for j = 1:numel(allViewIdentifiers)
            viewID = allViewIdentifiers(j);
            matchIndex = find(currentViewIdentifiers == viewID,1);
            if ~isempty(matchIndex)
                filledFiles(j) = currentFiles(matchIndex);
            else
                % Fill missing view with an empty string.
                filledFiles(j) = "";
            end
        end
          
        % Assign the aligned and filled files to the output cell array.
        filledImageFiles{i} = filledFiles;
    end
 
    filledImageFiles = cat(2,filledImageFiles{:});

    function viewIdentifiers = helperExtractViewIdentifiers(fileNames)
        % Example of extracting view numbers from filenames.
        % Assumes filenames are in the format "view<number>.ext".
        viewIdentifiers = zeros(numel(fileNames),1);
        for k = 1:numel(fileNames)
            [~,name] = fileparts(fileNames{k});
            % Extract the numeric part of the filename.
            numStr = regexp(name,"\d+","match");
            if ~isempty(numStr)
                viewIdentifiers(k) = str2double(numStr{1});
            end
        end
    end
end