Why do I get this error?

I = read_raw('D:\arstonFlowRateBPL\Dnoise\DnoiseA\Default');%%   The folder path containing a set of dark count pictures
Nd = 5;% pixel window 
[nd, vard] = estimate_darkcurrent(I,Nd);%% camera dark current and its variance£»
%% Target:relection standard ,Determine the system noise characteristics and the coherence factor
%sample_path is a collection of data paths of reflection standard,which can be observed from 'estimate_var'.
x1 = 250;x2 = 290;y1 = 450;y2 = 490; % The range selection is determined by the location of the fat emulsion
T = 20;t = 100; % T is the camera exposure time£¬t is the time between taking photos

function II = read_raw(sample_path)
Readfiles = dir(fullfile(sample_path, '*.raw'));%% Data Path

for number = 1:length(Readfiles)
    filename = strcat(sample_path,Readfiles(number).name);
    fid1 = fopen(filename);     
    data1 = fread(fid1,964*646,'uint16');  %% Data attributes
    image1 = reshape(data1,646,964)';
    fclose(fid1);
    I1 = image1;
    if number == 1
        II = I1; 
    else
        II(:,:,number) = I1; 
    end
    if number>100 
        break
    end
end

Output argument "II" (and maybe others) not assigned during call to "read_raw".

Error in main_program__Systemc_alibration (line 4)

I = read_raw('D:\arstonFlowRateBPL\Dnoise\DnoiseA\Default');%% The folder path containing a set of dark count pictures

Answer 1

[Image Analyst]

You never got into the if block to set II. Try initializing it to null to avoid that particular error

I = read_raw('D:\arstonFlowRateBPL\Dnoise\DnoiseA\Default');%%   The folder path containing a set of dark count pictures
Nd = 5;% pixel window 
[nd, vard] = estimate_darkcurrent(I,Nd);%% camera dark current and its variance£»
%% Target:relection standard ,Determine the system noise characteristics and the coherence factor
%sample_path is a collection of data paths of reflection standard,which can be observed from 'estimate_var'.
x1 = 250;x2 = 290;y1 = 450;y2 = 490; % The range selection is determined by the location of the fat emulsion
T = 20;t = 100; % T is the camera exposure time£¬t is the time between taking photos

function II = read_raw(sample_path)
II = [];

Readfiles = dir(fullfile(sample_path, '*.raw'));%% Data Path
if isempty(Readfiles)
    errorMessage = sprintf('No files found in folder "%s"!', sample_path);
    uiwait(errordlg(errorMessage))
end

for number = 1:length(Readfiles)
    filename = strcat(sample_path,Readfiles(number).name);
    fid1 = fopen(filename);     
    data1 = fread(fid1,964*646,'uint16');  %% Data attributes
    image1 = reshape(data1,646,964)';
    fclose(fid1);
    I1 = image1;
    if number == 1
        II = I1; 
    else
        II(:,:,number) = I1; 
    end
    if number>100 
        break
    end
end
% Warn user if we never assigned II
if isempty(II)
    errorMessage = 'You never assigned II to be anything!'
    uiwait(errordlg(errorMessage))
end
end