Unable to process multiple files in Matlab GUI

Hello Everyone,

I have created a Matlab GUI where I would load multiple images by clicking a button. I would then segment all the images together by clicking the segment button. I could load mutiple images together properly by clicking the Load button . However, I am unable to segment those mutiple images together when I click the Segment button. I have attached few images. Any help would be appreciated. Please find my code below:

function varargout = ngui(varargin)
% NGUI MATLAB code for ngui.fig
%      NGUI, by itself, creates a new NGUI or raises the existing
%      singleton*.
%
%      H = NGUI returns the handle to a new NGUI or the handle to
%      the existing singleton*.
%
%      NGUI('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in NGUI.M with the given input arguments.
%
%      NGUI('Property','Value',...) creates a new NGUI or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before ngui_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to ngui_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help ngui

% Last Modified by GUIDE v2.5 30-Mar-2021 22:59:22

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @ngui_OpeningFcn, ...
                   'gui_OutputFcn',  @ngui_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before ngui is made visible.
function ngui_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to ngui (see VARARGIN)

% Choose default command line output for ngui
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes ngui wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = ngui_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;


% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% Specify the folder where the files live.
myFolder = 'D:\regionGrowing_MLT\Images';
% Check to make sure that folder actually exists.  Warn user if it doesn't.
if ~isfolder(myFolder)
    errorMessage = sprintf('Error: The following folder does not exist:\n%s\nPlease specify a new folder.', myFolder);
    uiwait(warndlg(errorMessage));
    myFolder = uigetdir(); % Ask for a new one.
    if myFolder == 0
         % User clicked Cancel
         return;
    end
end
% Get a list of all files in the folder with the desired file name pattern.
filePattern = fullfile(myFolder, '*.jpg'); % Change to whatever pattern you need.
theFiles = dir(filePattern);
num_files=length(theFiles);
imgs=cell(1,num_files);
for k = 1 : length(theFiles)
    baseFileName = theFiles(k).name;
    fullFileName = fullfile(theFiles(k).folder, baseFileName);
    fprintf(1, 'Now reading %s\n', fullFileName);
    % Now do whatever you want with this file name,
    % such as reading it in as an image array with imread()
    imageArray = imread(fullFileName);
    imshow(imageArray);  % Display image.
    drawnow; % Force display to update immediately.
    InputImage=imageArray(:,k);
    
    axes(handles.axes1);
   
    
    handles.InputImage=InputImage;
end

    % Update handles structure
guidata(hObject, handles);

% --- Executes on button press in pushbutton2.
function pushbutton2_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

for k = 1 : length(theFiles)
    InputImage=handles.InputImage;

%     InputImage=handles.InputImage;
    InputImage=rgb2gray(InputImage);
    x=300; y=340;
    a=imgaussfilt(InputImage,2);
    b=adapthisteq(a);
    m=regiongrowing_MLT(b,x,y,12);
    m=imfill(m,'holes');
    % figure,imshow(m)
    bw=imbinarize(m);
    bw=bwareafilt(bw,1);
    % figure,imshow(bw)
    I = imresize(InputImage,.5);  %-- make image smaller 
    m1 = imresize(bw,.5);  %     for fast computation
    % subplot(2,2,1); imshow(I); title('Input Image');
    % subplot(2,2,2); imshow(m1); title('Initialization');
    % subplot(2,2,3); title('Segmentation');
    seg = region_seg(I, m1, 30); %-- Run segmentation
    % subplot(2,2,4); imshow(seg); title('Global Region-Based Segmentation');
    imshow(seg);
    axes(handles.axes2);
    handles.seg=seg;
end
guidata(hObject, handles);

The following error message is displayed

Unrecognized function or variable 'theFiles'.

Error in ngui>pushbutton2_Callback (line 124)

for k = 1 : length(theFiles)

Error in gui_mainfcn (line 95)

feval(varargin{:});

Error in ngui (line 42)

gui_mainfcn(gui_State, varargin{:});

Error in

matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)ngui('pushbutton2_Callback',hObject,eventdata,guidata(hObject))

Error while evaluating UIControl Callback.

Answer 1

[Image Analyst]

The files is not defined in that pushbutton. Please attach your .fig file so I can fix it.

https://matlab.fandom.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.28s.29.3F

Your pushbutton1_Callback() should fill up a listbox, not just repeatedly overwrite an array imageArray and then do nothing with it.

[Warid Islam]

Hi Image Analyst,

Please find my .fig file below.

[Image Analyst]

OK, but where is ngui.m? None of the code you attached above is a full m-file like GUIDE would have created. Please attach ngui.m with the paper clip icon.

[Warid Islam]

Hi Image Analyst,

I am sorry not to have attached the ngui.m file before. Please find the file in this attachment.

[Warid Islam]

Hi @Image Analyst,

I have managed to fix the above issue. However, I am facing a new problem. The images are loaded together properly when I click the Load button. But, When I click the Segment button, the segmentation is done only on the last image on the folder rather than on all the images from the folder. It seemed the images in the Load pushbutton callback function are overwritten rather than being stored properly.

function varargout = ngui(varargin)
% NGUI MATLAB code for ngui.fig
%      NGUI, by itself, creates a new NGUI or raises the existing
%      singleton*.
%
%      H = NGUI returns the handle to a new NGUI or the handle to
%      the existing singleton*.
%
%      NGUI('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in NGUI.M with the given input arguments.
%
%      NGUI('Property','Value',...) creates a new NGUI or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before ngui_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to ngui_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help ngui

% Last Modified by GUIDE v2.5 06-Apr-2021 00:32:44

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @ngui_OpeningFcn, ...
                   'gui_OutputFcn',  @ngui_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before ngui is made visible.
function ngui_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to ngui (see VARARGIN)

% Choose default command line output for ngui
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes ngui wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = ngui_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;


% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)

% hObject    handle to pushbutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% Specify the folder where the files live.
myFolder = 'D:\regionGrowing_MLT\';
% Check to make sure that folder actually exists.  Warn user if it doesn't.
if ~isfolder(myFolder)
    errorMessage = sprintf('Error: The following folder does not exist:\n%s\nPlease specify a new folder.', myFolder);
    uiwait(warndlg(errorMessage));
    myFolder = uigetdir(); % Ask for a new one.
    if myFolder == 0
         % User clicked Cancel
         return;
    end
end
% Get a list of all files in the folder with the desired file name pattern.
filePattern = fullfile(myFolder, '*.jpg'); % Change to whatever pattern you need.
theFiles = dir(filePattern);
num_files=length(theFiles);
imgs=cell(1,num_files);
for k = 1 : length(theFiles)
    baseFileName = theFiles(k).name;
    fullFileName = fullfile(theFiles(k).folder, baseFileName);
    fprintf(1, 'Now reading %s\n', fullFileName);
    % Now do whatever you want with this file name,
    % such as reading it in as an image array with imread()
    imageArray = imread(fullFileName);
    imshow(imageArray,'parent',handles.axes1);  % Display image.
    drawnow; % Force display to update immediately.
    
    InputImage=imageArray;
    
   

   
    handles.theFiles=theFiles;
    handles.InputImage=InputImage;
end
setappdata(handles.pushbutton1,'img',InputImage);
    % Update handles structure
guidata(hObject, handles);

% --- Executes on button press in pushbutton2.
function pushbutton2_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
J = getappdata(handles.pushbutton1,'img');
J=rgb2gray(J);
x=300; y=340;
a=imgaussfilt(J,2);
b=adapthisteq(a);
m=regiongrowing_MLT(b,x,y,12);
m=imfill(m,'holes');
% figure,imshow(m)
bw=imbinarize(m);
bw=bwareafilt(bw,1);
% figure,imshow(bw)
I = imresize(J,.5);  %-- make image smaller 
m1 = imresize(bw,.5);  %     for fast computation

seg = region_seg(J, m1, 30); %-- Run segmentation
imshow(seg,'parent',handles.axes2);

    handles.seg=seg;
    guidata(hObject, handles);

[Rik]

Why do you insist on using GUIDE? The first 75 lines of the code you posted are just uninformative bloat.

[Warid Islam]

Hi @Rik,

I wanted to build a GUI. That's why I was referring to GUIDE. Are there any other options on building a GUI?

[Rik]

For general advice and examples for how to create a GUI (and avoid using GUIDE), have look at this thread.

[Warid Islam]

Hi Rik,

Thank you for the link.

[Warid Islam]

Hi @Rik,

I tried using the APP DESIGNER. I could load the image in the GUI but I am having some errors while segmenting the image by clicking the Segment button.

Error using matlab.ui.control.Image/set.ImageSource (line 123)
ImageSource value must be a valid file path, or an m-by-n-by-3 color data matrix.

Error in new/SegmentButtonPushed (line 69)
app.Image2.ImageSource=finalimg;
 
Error using matlab.ui.control.internal.controller.ComponentController/executeUserCallback (line 386)
Error while evaluating Button PrivateButtonPushedFcn.

[Rik]

A GUI is a graphical user interface. You should make sure your code works first, before you build a GUI around it.

Regarding that error message, what don't you understand from it? You wrote the code, so you must understand what you want to do. What are you providing as input? The error message suggest it should be either a path, or an RGB image.