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: spm_preproc.m
    path of file: ./repos/ExploreASL/External/SPMmodified
    
    the code of the file until where you have to start completion: function results = spm_preproc(varargin)
% Combined Segmentation and Spatial Normalisation
%
% FORMAT results = spm_preproc(V,opts)
%  V    - image to work with
%  opts - options
%  opts.tpm      - n tissue probability images for each class
%  opts.ngaus    - number of Gaussians per class (n+1 classes)
%  opts.warpreg  - warping regularisation
%  opts.warpco   - cutoff distance for DCT basis functions
%  opts.biasreg  - regularisation for bias correction

    
function results = spm_preproc(varargin)
% Combined Segmentation and Spatial Normalisation
%
% FORMAT results = spm_preproc(V,opts)
%  V    - image to work with
%  opts - options
%  opts.tpm      - n tissue probability images for each class
%  opts.ngaus    - number of Gaussians per class (n+1 classes)
%  opts.warpreg  - warping regularisation
%  opts.warpco   - cutoff distance for DCT basis functions
%  opts.biasreg  - regularisation for bias correction
%  opts.biasfwhm - FWHM of Gausian form for bias regularisation
%  opts.regtype  - regularisation for affine part
%  opts.fudge    - a fudge factor
%  opts.msk      - unused
%__________________________________________________________________________
% Copyright (C) 2005-2011 Wellcome Trust Centre for Neuroimaging

% John Ashburner
% $Id: spm_preproc.m 4916 2012-09-11 19:15:53Z guillaume $


SVNid     = '$Rev: 4916 $';

if ~isdeployed, addpath(fullfile(spm('Dir'),'toolbox','OldSeg')); end