You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: CBIG_ComputeCorrelationProfileVol2Vol2mm.m
    path of file: ./repos/CBIG/utilities/matlab/FC
    
    the code of the file until where you have to start completion: function CBIG_ComputeCorrelationProfileVol2Vol2mm(output_file, threshold, mask_file, input_file_txt, roi_file, regress_bool)

% CBIG_ComputeCorrelationProfileVol2Vol2mm(output_file, threshold, mask_file, input_file_txt, roi_file, regress_bool)
%
% output_file:    output file name
% threshold:      relative threshold of correlation matrix for binarization
% mask_file:      volumetric mask
% input_file_txt: a text file containing input file list
% roi_file:       seed regions in volume
% regress_bool (not used)
% 
% Compute volume to volume correlation profiles.
%
% Written by CBIG under MIT license: https://github.com/ThomasYeoLab/CBIG/blob/master/LICENSE.md


% read in roi mask.
roi_mask = MRIread(roi_file);
roi_index = find(roi_mask.vol == 1);
mask = MRIread(mask_file);
mask_index = find(mask.vol == 1);

% read in input files.
fid = fopen(input_file_txt, 'r');

    
function CBIG_ComputeCorrelationProfileVol2Vol2mm(output_file, threshold, mask_file, input_file_txt, roi_file, regress_bool)

% CBIG_ComputeCorrelationProfileVol2Vol2mm(output_file, threshold, mask_file, input_file_txt, roi_file, regress_bool)
%
% output_file:    output file name
% threshold:      relative threshold of correlation matrix for binarization
% mask_file:      volumetric mask
% input_file_txt: a text file containing input file list
% roi_file:       seed regions in volume
% regress_bool (not used)
% 
% Compute volume to volume correlation profiles.
%
% Written by CBIG under MIT license: https://github.com/ThomasYeoLab/CBIG/blob/master/LICENSE.md


% read in roi mask.
roi_mask = MRIread(roi_file);
roi_index = find(roi_mask.vol == 1);
mask = MRIread(mask_file);
mask_index = find(mask.vol == 1);

% read in input files.
fid = fopen(input_file_txt, 'r');
i = 0;
while(1);
   tmp = fscanf(fid, '%s\n', 1);
   if(isempty(tmp))
       break
   else
       i = i + 1;
       input_files{i} = tmp;
   end