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: greedyROI_corr.m
    path of file: ./repos/CaImAn-MATLAB/utilities
    
    the code of the file until where you have to start completion: function [Ain, Cin,  bin, fin, center, res] = greedyROI_corr(Y, K, options, sn, debug_on, save_avi)
%% a greedy method for detecting ROIs and initializing CNMF. in each iteration,
% it searches the one with large (peak-median)/noise level and large local
% correlation
%% Input:
%   Y:  d X T matrx, imaging data
%   K:  scalar, maximum number of neurons to be detected.
%   options: struct data of paramters/options
%       d1:     number of rows
%       d2:     number of columns
%       gSiz:   maximum size of a neuron
%       nb:     number of background
%       min_corr: minimum threshold of correlation for segementing neurons
%   sn:     d X 1 vector, noise level of each pixel
%   debug_on: options for showing procedure of detecting neurons
%% Output:
%       Ain:  d X K' matrix, estimated spatial component
%       Cin:  K'X T matrix, estimated temporal component
%       bin:  d X nb matrix/vector, spatial components of the background
%       Cin:  nb X T matrix/vector, temporal components of the background
%       center: K' X 2, coordinate of each neuron's center
%       res:  d X T, residual after initializing Ain, Cin, bin, fin

%% Author: Pengcheng Zhou, Carnegie Mellon University.
% the method is an modification of greedyROI method used in Neuron paper of Eftychios
% Pnevmatikakis et.al. https://github.com/epnev/ca_source_extraction/blob/master/utilities/greedyROI2d.m
%% In each iteration of initializing neurons, it searchs the one with maximum
% value of (max-median)/noise * Cn, which selects pixels with high SNR and
% local correlation.

%% parameters

    
function [Ain, Cin,  bin, fin, center, res] = greedyROI_corr(Y, K, options, sn, debug_on, save_avi)
%% a greedy method for detecting ROIs and initializing CNMF. in each iteration,
% it searches the one with large (peak-median)/noise level and large local
% correlation
%% Input:
%   Y:  d X T matrx, imaging data
%   K:  scalar, maximum number of neurons to be detected.
%   options: struct data of paramters/options
%       d1:     number of rows
%       d2:     number of columns
%       gSiz:   maximum size of a neuron
%       nb:     number of background
%       min_corr: minimum threshold of correlation for segementing neurons
%   sn:     d X 1 vector, noise level of each pixel
%   debug_on: options for showing procedure of detecting neurons
%% Output:
%       Ain:  d X K' matrix, estimated spatial component
%       Cin:  K'X T matrix, estimated temporal component
%       bin:  d X nb matrix/vector, spatial components of the background
%       Cin:  nb X T matrix/vector, temporal components of the background
%       center: K' X 2, coordinate of each neuron's center
%       res:  d X T, residual after initializing Ain, Cin, bin, fin

%% Author: Pengcheng Zhou, Carnegie Mellon University.
% the method is an modification of greedyROI method used in Neuron paper of Eftychios
% Pnevmatikakis et.al. https://github.com/epnev/ca_source_extraction/blob/master/utilities/greedyROI2d.m
%% In each iteration of initializing neurons, it searchs the one with maximum
% value of (max-median)/noise * Cn, which selects pixels with high SNR and
% local correlation.

%% parameters
if exist('sn', 'var')
    Y_std = sn;
else
    Y_std = std(Y, 0, ndims(Y));
end