How can I insert live video into a MATLAB GUI using Image Acquisition Toolbox?

John Williams answered . 2024-12-21 00:36:11

guide

2. In the GUIDE Quick Start dialog, under GUIDE templates, select Blank GUI (Default) and press OK. This will open a blank GUI figure

3. Change the following properties of the figure. (You can double-click anywhere in the blank, gray figure area to open the Property Browser)

     a.  Name - Change to 'MyCameraGUI'
     b.  Tag - Change to 'MyCameraGUI'
     c.  Units - Change to 'pixels'
     d.  Position, Width - Change to 400
     e.  Position, Height - Change to 420

4. Click the button to the right of 'CloseRequestFcn' to auto-generate a callback function when the GUI is closed.

5. Insert an Axes into your GUI and modify its properties as follows:

     a.  Tag - Change to 'cameraAxes'
     b.  Units - Change to 'pixels'
     c.  Position, x - Change to 40
     d.  Position, y - Change to 40
     e.  Position, Width - Change to 320
     f.  Position, Height - Change to 240
     g.  Box - Change to 'on'
     h.  XTick - Change to '[]' by deleting all the entries.
          (Note that this automatically changes XTickMode to 'manual'.)
     i.  XTickLabel - Change to '' by highlighting and delete all the entries.
          (Note that this automatically changes XTickLabelMode to 'manual'.)
     j.  YTick - Change to '[]' by deleting all the entries.
          (Note that this automatically changes YTickMode to 'manual'.)
     k.  YTickLabel - Change to '' by highlighting and delete all the entries.
          (Note that this automatically changes YTickLabelMode to 'manual'.)

6. Insert a Push Button into your GUI and modify its properties as follows:

     a.  String - Change to 'Start Camera'
     b.  Tag - Change to 'startStopCamera'
     c.  Units - Change to 'pixels'
     d.  Position, x - Change to 20
     e.  Position, y - Change to 320
     f.  Position, Width - Change to 120
     g.  Position, Height - Change to 60

7. Repeat Step 6 with the following changes:

     a.  String - Change to 'Capture Image'
     b.  Tag - Change to 'captureImage'
     c.  Position, x - Change to 140

8. Repeat Step 6 with the following changes:

     a.  String - Change to 'Start Acquisition'
     b.  Tag - Change to 'startAcquisition'
     c.  Position, x - Change to 260

% Create video object
%   Putting the object into manual trigger mode and then
%   starting the object will make GETSNAPSHOT return faster
%   since the connection to the camera will already have
%   been established.
handles.video = videoinput('winvideo', 1);
set(handles.video,'TimerPeriod', 0.05, ...
    'TimerFcn',['if(~isempty(gco)),'...
                    'handles=guidata(gcf);'...                                 % Update handles
                    'image(getsnapshot(handles.video));'...                    % Get picture using GETSNAPSHOT and put it into axes using IMAGE
                    'set(handles.cameraAxes,''ytick'',[],''xtick'',[]),'...    % Remove tickmarks and labels that are inserted when using IMAGE
                'else '...
                    'delete(imaqfind);'...                                     % Clean up - delete any image acquisition objects
                'end']);
triggerconfig(handles.video,'manual');
handles.video.FramesPerTrigger = Inf; % Capture frames until we manually stop it

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

3. Modify the "--- Outputs from this function..." section of code so that it reads as follows:

% --- Outputs from this function are returned to the command line.
function varargout = myCameraGUI_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
handles.output = hObject;
varargout{1} = handles.output;

4. Modify the "--- Executes on button press in captureImage." section of code so that it reads as follows:

function captureImage_Callback(hObject, eventdata, handles)
% hObject    handle to captureImage (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% frame = getsnapshot(handles.video);
frame = get(get(handles.cameraAxes,'children'),'cdata'); % The current displayed frame
save('testframe.mat', 'frame');
disp('Frame saved to file ''testframe.mat''');

5. Modify the "--- Executes on button press in startAcquisition." section of code so that it reads as follows:

function startAcquisition_Callback(hObject, eventdata, handles)
% hObject    handle to startAcquisition (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Start/Stop acquisition
if strcmp(get(handles.startAcquisition,'String'),'Start Acquisition')
    % Camera is not acquiring. Change button string and start acquisition.
    set(handles.startAcquisition,'String','Stop Acquisition');
    trigger(handles.video);
else
    % Camera is acquiring. Stop acquisition, save video data,
    % and change button string.
    stop(handles.video);
    disp('Saving captured video...');
    
    videodata = getdata(handles.video);
    save('testvideo.mat', 'videodata');
    disp('Video saved to file ''testvideo.mat''');
    
    start(handles.video); % Restart the camera
    set(handles.startAcquisition,'String','Start Acquisition');
end

6. Modify the "Executes when user attempts to close myCameraGUI." section of code so that it reads as follows:

function myCameraGUI_CloseRequestFcn(hObject, eventdata, handles)
% hObject    handle to myCameraGUI (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hint: delete(hObject) closes the figure
delete(hObject);
delete(imaqfind);

myCameraGUI

The relevant files can be found below.

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