face detection - off button gui not working

Hi, i am working a face recognition system for my fyp but first i would like to ensure that the facial feature can be detected.

I have 2 question. I would like to add the video player into the gui but I am not sure which parts of the part i should amend. I try adding axes(handles.camerAxes) into my code and remove the videoplayer but face error.

Another question will be the off button. I want to off the videoplayer feature but there is error face.

Please help me as I am really new to matlab.

Thank you in advance.

function varargout = face_tracking(varargin)
% FACE_TRACKING MATLAB code for face_tracking.fig
%      FACE_TRACKING, by itself, creates a new FACE_TRACKING or raises the existing
%      singleton*.
%
%      H = FACE_TRACKING returns the handle to a new FACE_TRACKING or the handle to
%      the existing singleton*.
%
%      FACE_TRACKING('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in FACE_TRACKING.M with the given input arguments.
%
%      FACE_TRACKING('Property','Value',...) creates a new FACE_TRACKING or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before face_tracking_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to face_tracking_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 face_tracking

% Last Modified by GUIDE v2.5 28-Jan-2015 00:39:01

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @face_tracking_OpeningFcn, ...
                   'gui_OutputFcn',  @face_tracking_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 face_tracking is made visible.
function face_tracking_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 face_tracking (see VARARGIN)

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

% Update handles structure
guidata(hObject, handles);

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

% --- Outputs from this function are returned to the command line.
function varargout = face_tracking_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 when figure1 is resized.
function figure1_ResizeFcn(hObject, eventdata, handles)
% hObject    handle to figure1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% --- Executes on button press in cameraon.
function cameraon_Callback(hObject, eventdata, handles)
% hObject    handle to cameraon (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
faceDetector = vision.CascadeObjectDetector();

obj = imaq.VideoDevice('winvideo', 1, 'MJPG_320x240','ROI',[1 1 320 240]);
handles.vid=obj;

videoFrame = step(obj);

%Get a bounding box around the face
bbox            = step(faceDetector, videoFrame);

%Check if something was detected, otherwise exit
if numel(bbox) == 0
  errordlg('Face not detected. Please try again.');
end 

%Show coordinates of tracked face
videoOut = insertObjectAnnotation(videoFrame,'rectangle',bbox,'Face');
release(obj);
[hueChannel,~,~] = rgb2hsv(videoFrame);

noseDetector = vision.CascadeObjectDetector('Nose');
faceImage    = imcrop(videoFrame,bbox);

noseBBox     = step(noseDetector,faceImage);
% The nose bounding box is defined relative to the cropped face image.
% Adjust the nose bounding box so that it is relative to the original video
% frame.
noseBBox(1:2) = noseBBox(1:2) + bbox(1:2);

% Create a tracker object.
tracker = vision.HistogramBasedTracker;
initializeObject(tracker, hueChannel, noseBBox);
ROI = get(obj,'ROI');
videoSize = [ROI(3) ROI(4)];
videoPlayer  = vision.VideoPlayer('Position',[300 300 videoSize(1:2)+30]);

% Track the face over successive video frames until the video is finished.
%You could set here a finite number of frames to capture
while 1

      % Extract the next video frame
      videoFrame = step(obj);

      % RGB -> HSV
      hsv=rgb2hsv(videoFrame);

      % Track using the Hue channel data
      bbox = step(tracker, hsv(:,:,1));

      % Insert a bounding box around the object being tracked
      videoOut = insertObjectAnnotation(videoFrame,'rectangle',bbox,'Face');

      % Display the annotated video frame using the video player object
      step(videoPlayer, videoOut);
  end

guidata(hObject,handles);

% Release resources
release(obj);
release(videoPlayer);

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

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

[Geoff Hayes]

Eliza - you mention that you are facing an error. Please describe the error and include all relevant text associated with the error.