GUI with camera input error

I just learn to use MATLAB to make GUI for camera input. I have got 1 sample for me to learn from in file exchange and i tried it out myself but it doesnt work.

I need to capture image using webcam with a click on the button for futher processing. however error message pop up when i click the button.

the error message are:

??? Error using ==> feval
Undefined function or method 'startstopcamera_Callback' for input arguments of type 'double'.

Error in ==> gui_mainfcn at 96
        feval(varargin{:});

Error in ==> camera at 42
    gui_mainfcn(gui_State, varargin{:});

Error in ==>
@(hObject,eventdata)camera('startstopcamera_Callback',hObject,eventdata,guidata(hObject))

??? Error while evaluating uicontrol Callback

and my code for gui are:

function varargout = camera(varargin)

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @camera_OpeningFcn, ...
                   'gui_OutputFcn',  @camera_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

function camera_OpeningFcn(hObject, eventdata, handles, varargin)

handles.output = hObject;

handles.video = videoinput('winvideo', 1);
set(handles.video,'TimerPeriod', 0.05, ...
'TimerFcn',['if(~isempty(gco)),'...
'handles=guidata(gcf);'...
'image(getsnapshot(handles.video));'... 
'set(handles.cameraAxes,''ytick'',[],''xtick'',[]),'... 
'else '...
'delete(imaqfind);'... 
'end']);
triggerconfig(handles.video,'manual');

guidata(hObject, handles);

uiwait(handles.myCameraGUI);

function varargout = myCameraGUI_OutputFcn(hObject, eventdata, handles)

handles.output = hObject;
varargout{1} = handles.output;

function startStopCamera_Callback(hObject, eventdata, handles)

if strcmp(get(handles.startStopCamera,'String'),'Start Camera')

set(handles.startStopCamera,'String','Stop Camera')
start(handles.video)
else

set(handles.startStopCamera,'String','Start Camera')
stop(handles.video)
end

can any1 point out my problem?? and it will be better if you link more samples for me to learn. Thanks in advance.

Answer 1

[Walter Roberson]

You have a function named startStopCamera_Callback but you are trying to call upon the function named startstopcamera_Callback . Notice the 's' vs 'S' and 'c' vs 'C' .

You will have to change the callback associated with some uicontrol or other whose code you do not show here. Probably it is part of a .fig file.

This sort of problem occurs regularly when people rename their GUIDE GUI. (Just one more of the reasons I don't use GUIDE...)

[Hock Hock]

oh..ok got it.. i will try other method to create GUI. thanks