how to solve Error Output argument "variable_name" (and maybe others) not assigned during call to "function_name".

Good evening to all my brothers and sisters. my codes give some issue that confuse me.

these the codes are:

Img = imread('Adok_Karo1_biner.jpg');
BW = im2bw(Img, graythresh(Img));
BW = bwareaopen(BW, 5);
re = BW;
while 1
    %Fcn 'lines' separate lines in text
    [fl, re]=lines(re);
    imgn=fl
    
    %% Fcn projProfile_Horizontal separate characters in line
    [char_out, num_char, L, Ne] = projProfile_Horizontal(imgn);
    %% end

    set(handles.text11, 'String',Ne);
    
    %% Objects extraction
    NumberOfCharacter = length(num_char); % number of characters in a line That had been stored in cell Num
    
    for m = 1 : Ne % Ne is Number of labelled object
        if Ne == 2
            L1 = ismember(L, 1); % storing the labelled object 1 to L1
            L2 = ismember(L, 2); % storing the labelled object 2 to L2
            char_out = L1; % first object on a cropped character window
            char_out2 = L2; % second object on a cropped character window
            figure();
            %showing first object
            subplot(1, 2, 1);
            imshow(char_out);
            caption = sprintf('character #%d', 1);
            title(caption, 'FontSize', 20);
            %Showing second object
            subplot(1,2,2);
            imshow(char_out2);
            caption2 = sprintf('character #%d', 2);
            title(caption2, 'FontSize', 20);
        end
    end
    %% End
    
    BW2 = bwmorph(char_out,'thin',Inf);
    imrotate(BW2,0);
    imshow(~BW2);
    z=imresize(BW2,[50 50]);
    %z = imresize(BW2, [42 24]); % [m, n] format
    z = feature_extract(z); % Image Zoning 3x3
    
    FeatureOutTest = z; % new modified
    
    save('FeatureOutTest.mat','FeatureOutTest'); % new modified
    
    test
    
    pause(0.5);
% end
    if isempty(re)  %See variable 're' in Fcn 'lines'! 
                    %To stop "while" iteration when there aren't any remaining-
                    %character and off course the line itself in "re" image
        break;
    end    
end

and function for projProfile_Horizontal. m is :

function [char_out, num_char, L, Ne] = projProfile_Horizontal(areaOpeningImage)
    %% projProfile_Horizontal is used to separate text line image into characters based on its horizontal projection 
    % char_out : a character output.
    % num_char : number character in text line image.
    % L : labelled characters in a cropped image window, so that we know how many image
    %       in a cropped image window.
    % Ne : number of labelled object in a cropped image window
    %%
    
    %clc;    % Clear the command window.
    %close all;  % Close all figures (except those of imtool.)
    % clear;  % Erase all existing variables. Or clearvars if you want.
    workspace;  % Make sure the workspace panel is showing.
    format long g;
    format compact;
    fontSize = 20;
    %areaOpeningImage =imread('D:\pcd\tester\Segmentation\data_test\ImageAnalyst\Adok_karo1_biner.jpg');
    % Show image
    figure(1)
    h1 = subplot(4, 12, 1:12);
    imshow(areaOpeningImage);
    impixelinfo
    title('INPUT IMAGE WITH NOISE')
    %% Convert to gray scale
    if size(areaOpeningImage, 3) == 3 % RGB image
        areaOpeningImage=rgb2gray(areaOpeningImage);
        threshold = graythresh(areaOpeningImage);
        binaryImage = im2bw(areaOpeningImage, threshold);
        imshow(binaryImage);
        axis('image', 'on'); % Display tick marks.
        title('Binary Image', 'FontSize', fontSize);

    end

    
    %% Find horizontal profile
    binaryImage = areaOpeningImage; % Area Opening Image is assumed euqal to binaryImage :D (just a name)
    h2 = subplot(4, 12, 13:24);
    horizontalProfile = sum(binaryImage, 1);
    plot(horizontalProfile, 'b-');
    title('Horizontal Profile', 'FontSize', fontSize);
    grid on;
    %%
    
    %% Find dividing lines between the characters.
    props = regionprops(horizontalProfile == 0, 'Centroid'); %centroid of all gaps
    xyCentroids = [props.Centroid];
    dividingLines = xyCentroids(1:2:end); % get only the gaps centroid
    for k = 1 : length(dividingLines)
        thisX = dividingLines(k);
        %line(h1, [thisX, thisX], ylim(h1), 'Color', 'r');
        line([thisX, thisX], ylim(h1), 'Parent', h1, 'Color', 'r');
        %line(h2, [thisX, thisX], ylim(h2), 'Color', 'r');
        line([thisX, thisX], ylim(h2), 'Parent', h2, 'Color', 'r');
    end
    %%
    
    %% Enlarge figure to full screen.
    set(gcf, 'Units', 'Normalized', 'Outerposition', [0, 0.05, 1, 0.95]);
    drawnow;
    %%
    
    %% Extract each letter.
    fontSize = 12;
    num_char = {};
    char_coord = 1; 
    for k = 1 : length(dividingLines) - 1
        thisX = round(dividingLines(k));
        nextX = round(dividingLines(k+1));
        subplot(4, 12, 24 + k);
        thisLetter = binaryImage(:, thisX:nextX);
        [L, Ne] = bwlabel(thisLetter);

        char_unpads = pads_crop(thisLetter);
        char_pads = padarray(char_unpads,[2 2], 'both');
        imshow(thisLetter);
        caption = sprintf('Letter #%d', k);
        title(caption, 'FontSize', fontSize);
        char_out = char_pads;
        num_char{1, char_coord} = {num_char, char_out}; % storing all characters into cell
        char_coord = char_coord + 1; % plus the coordinat by 1
        break; % new editted, so that only take a word per line
    end
    %%
end

function img_out = pads_crop(thisCharacter)
    % cropping the pads
    [f, c]=find(thisCharacter); % finding row(f) and column(c) indices
    img_out=thisCharacter(min(f):max(f),min(c):max(c));%Cropping all pad of image
    % end 
end
	

The Error is :

Output argument "char_out" (and maybe others) not assigned during call to "projProfile_Horizontal".
Error in DetectAksara>btnRecognize_Callback (line 352)
    [char_out, num_char, L, Ne] = projProfile_Horizontal(imgn);
Error in gui_mainfcn (line 95)
        feval(varargin{:});
Error in DetectAksara (line 42)
    gui_mainfcn(gui_State, varargin{:});
Error in
matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)DetectAksara('btnRecognize_Callback',hObject,eventdata,guidata(hObject)) 
352     [char_out, num_char, L, Ne] = projProfile_Horizontal(imgn);

i had looked at the projProfile_Horizontal function and ran it separately, but it worked properly.

what should i do to solve this error ?

Answer 1

[Jan]

If length(dividingLines) - 1 equals 0, the loop is not entered and char_out is not created.

Use the debugger to find out, what's going on: Set a breakpoint in the first line of the failing function and step through the code line by line. Then you will see directly, why the output is not defined.