Help to subtract two images with gui

Hello. I need help with gui. 1) I have 2 pictures that I want to subtract and do not know how to code. The two images are open in two axes. The subtract will appear in a third axes. 2)have to move from string to double?

thank you very much!

Answer 1

[Image Analyst]

String to double??? No. Just cast to floating point (so you won't get clipping at 0) and subtract:

diffImage = double(image1) - double(image2);

Of course you already have image1 and image2 or else you wouldn't have been able to display them in their axes.

Answer 2

[Sophie]

I have this:

% --- Executes on button press in psr. psr_Callback function (hObject, eventdata, handles) diffImage = double (img0) - double (img90); axes (handles.ps1) image (diffImage)

There is an error that says:

?? Undefined function or variable 'img0'.

Error in ==> entornografico2> psr_Callback at 233 diffImage = double (img0) - double (img90);

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

Error in ==> entornografico2 at 42 gui_mainfcn (gui_State, varargin {:});

Error in ==> @ (hObject, eventdata) gui1 ('psr_Callback', hObject, eventdata, guidata (hObject))

?? Error while uicontrol Callback Evaluating

Thank you.

[Image Analyst]

img0 is not in scope. You need to make it in scope - make it so that your callback can see it. See the FAQ: http://matlab.wikia.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.28s.29.3F

Please post comments/follow-up questions as comments to my Answer, not as Answers to your questions.