I want to add grid on my image in matlab GUI

I have a problem. Below is my code...when ever i check the box, the image is replaced with blank screen with a vertical line in middle..Help me please

function show_grid_Callback(hObject, eventdata, handles) % hObject handle to show_grid (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) if (get(handles.show_grid, 'Value')) % rgb = imread('IK.jpg');

 imshow(handles.img,'Parent', handles.axes3);
hold on
M = size(handles.img,1);
N = size(handles.img,2);
a=str2double(get(handles.edit3, 'String')); b=str2double(get(handles.edit5, 'String'));

for k = 1:a:M x = [1 N]; y = [k k];

    plot(x,y,'Color','black','LineStyle','-','Parent', handles.axes3);
    set(findobj('Tag','MyGrid'),'Visible','on')
%   plot(x,y,'Color','k','LineStyle',':');
end
for k = 1:b:N x = [k k]; y = [1 M];

    plot(x,y,'Color','black','LineStyle','-','Parent', handles.axes3);
    set(findobj('Tag','MyGrid'),'Visible','on')
%     plot(x,y,'Color','k','LineStyle',':');
end
hold off else imshow(handles.img,'Parent', handles.axes3); end % Hint: get(hObject,'Value') returns toggle state of show_grid guidata(hObject, handles);

[Image Analyst]

What is the point of the set(findobj) line?

[Uzair]

I was trying something i found in another question...anyway...I commented it out later

Answer 1

[David Sanchez]

Image Analyst is right. I simplified the code to this:

I = imread('cameraman.tif');
imshow(I) 
hold on
M = size(I,1);
N = size(I,2);
a=5; 
b=10;
for k = 1:a:M
    x = [1 N]; 
    y = [k k];
    plot(x,y,'Color','black','LineStyle','-');
    set(findobj('Tag','MyGrid'),'Visible','on')
end
for k = 1:b:N 
    x = [k k]; 
    y = [1 M];
    plot(x,y,'Color','black','LineStyle','-');
    set(findobj('Tag','MyGrid'),'Visible','on')
end
hold off

And the desired grid shows up. The problem might be in the figure handle.

Answer 2

[David Sanchez]

You get a vertical line because you are plotting a vertical line. The values of both elements of your x array are the same

x=[k k];

which will end up in a vertical line whatever the values of y are.

... ... for k = 1:b:N x = [k k]; y = [1 M];

    plot(x,y,'Color','black','LineStyle','-','Parent', handles.axes3);
    set(findobj('Tag','MyGrid'),'Visible','on')
%     plot(x,y,'Color','k','LineStyle',':');
end

[Uzair]

so what do u suggest i should do ?

[Image Analyst]

But he didn't always have the same x. k went from 1 to N in steps of b and he had hold on so it should have drawn and retained lots of vertical lines, not just one. Just off the top of my head it looks like he should have had vertical lines at 1, (1+b), (1+2*b), .... etc.

[Uzair]

Al tough code works perfectly fine when i run it seperately...but when i modify this code for my GUI ...it's give me wrong results