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: Check3DCellSegmentationProcess.m
    path of file: ./repos/u-shape3D/software
    
    the code of the file until where you have to start completion: classdef Check3DCellSegmentationProcess < MaskProcess & NonSingularProcess

 % Check3DCellSegmentationProcess - create and display binary 3D mask using Mesh3DProcess outputs.
%
% Copyright (C) 2024, Danuser Lab - UTSouthwestern 
%
% This file is part of Morphology3DPackage.
% 
% Mo
    
function defaultParams = getDefaultParams(owner,varargin)
            % check inputs
            ip = inputParser;
            ip.addRequired('owner', @(x) isa(x, 'MovieObject'));
            ip.addOptional('outputDir', owner.outputDirectory_, @ischar);
            ip.parse(owner)

            nChan = numel(owner.channels_);
            defaultParams = struct();                        
        
            defaultParams.ChannelIndex = 1:numel(owner.channels_); % see class method setPara above
            % set more default parameters
            defaultParams.OutputDirectory = fullfile(ip.Results.outputDir,'Morphology', 'Analysis','Threshold');        
            defaultParams = prepPerChannelParams(defaultParams, nChan);                    
        end