How to re size a too big image into small by keeping original values.

If you want, you can run this function to turn off benign warnings in your m-file.

function TurnOffWarnings
  try
    % To set the warning state, you must first know the message identifier for the one warning you want to enable. 
    % Query the last warning to acquire the identifier.  For example: 
    % warnStruct = warning('query', 'last')
    % messageID = warnStruct.identifier
    % messageID =
    %    MATLAB:concatenation:integerInteraction
    
    % Turn off this warning "Warning: Image is too big to fit on screen; displaying at 33% "
    warning('off', 'Images:initSize:adjustingMag');
    
    % Get rid of warning about roipolyold being deprecated: 
    % "Warning: Function ROIPOLYOLD will be removed in the future. Use ROIPOLY instead"
    warning('off', 'images:removing:function');
    
    % Get rid of warning about directory already existing: 
    % "Warning: Directory already exists."
    warning('off', 'MATLAB:MKDIR:DirectoryExists');

    % Turn off note "Warning: Added specified worksheet." that appears in the command window.
    warning('off', 'MATLAB:xlswrite:AddSheet');
  catch ME
    errorMessage = sprintf('Error in function %s() at line %d.\n\nError Message:\n%s', ...
      ME.stack(1).name, ME.stack(1).line, ME.message);
    fprintf(1, '%s\n', errorMessage);
    WarnUser(errorMessage);
  end
  return; % from TurnOffWarnings

You can add or delete warnings as you wish.