Set default value textedit

Hello,

I am new in GUI. I have created some GUI script in order to process images that contains the following syntax:

function Num_seg_Callback(hObject, eventdata, handles)
  numseg=str2double(get(hObject,'String'));
  if isempty(numseg)   %I have also tried isnan
      numseg=1;
  end
  handles.numseg=numseg;
  guidata(hObject,handles);

I would like to set 1 as the default value of a text edit object (numseg) which I use below in my code. This syntax is giving an error (Reference to non-existent field 'numseg') and it works only if I first write a number and then delete it. Does anyone have an idea of why is this occurring? Why it doesn't work the first time I run it?

I have also tried: if isnan(numseg) set (handles.numseg,'String',1); end ...

[Rik]

Is specifically this function itself returning an error? Or did you forget to initialize the numseg field?

[MARIA RODRIGUEZ SANZ]

I Rik

Thanks for your response,

I think that it triggers the error when I try to call numseg in this code below:

%====================================================================================
%                         BOTON SEGMENTACION
%====================================================================================
% --- Executes on button press in Boton_segmentar.
function Boton_segmentar_Callback(hObject, eventdata, handles)
% hObject    handle to Boton_segmentar (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
%SI EXISTE LA IMAGEN CORTADA, LA SEGMENTAS Y SI NO HA CORTADO NADA LO HACES
%CON LA CRUDA:

      %------------------------------------------------------------------------------
      % PREPROCESAMOS LA IMAGEN PARA SEGMENTAR
      %------------------------------------------------------------------------------
      Imagengs=rgb2gray(Imagen_segmentar);
      histeq=adapthisteq(Imagengs);  %Ecualizacion del histograma
      ajus = imadjust(histeq,[0.3  0.7],[0  1]); %Ajustamos contraste
      edges= edge(ajus,'Canny');   %Calculamos los bordes
      fil=imdilate(edges,ones(7,7)); %Dilatamos los puntos
      fil=imcomplement(fil);   %Creamos la complementaria

      %-----------------------------------------------------------------------------
      % SEGMENTACION
      %-----------------------------------------------------------------------------
      lab=bwlabel(fil);   %Marcamos las etiquetas de las regiones 
      BW2 = bwareafilt(fil,handles.numseg); %Eliminamos todos los segmentos que no sean del strip
      BW2_fill=imfill(BW2,'holes'); %Rellenamos los huecos que puedan quedar en medio del strip
      strip=bwlabel(BW2_fill);  %Volvemos a guardar las etiquetas de los nuevos segmentos

      %-------------------------------------------------------------------
      %MOSTRAMOS EL RESULTADO DE LA SEGMENTACION
      %--------------------------------------------------------------------
      axes(handles.plot1) %Le indicamos que estamos trabajando en el plot1
      cla  %Borra la imagen anterior que haya en el current axes
      overlay2 = imOverlay(Imagen_segmentar, BW2_fill, [.3 1 .3]);
      imshow(overlay2); %Muestra la imagen segmentada

[MARIA RODRIGUEZ SANZ]

I don't know what do you mean with initialize the field... Sorry

Answer 1

[Rik]

In your OpeningFcn, you need to set a value for the numseg field. That way, the field exists in your handles struct and that other function can use it.

[MARIA RODRIGUEZ SANZ]

Thank you. That worked perfect! So simply! No if statements were necessary...