code to pas a value

Sir this my code.

mask = bwconvhull(binaryImage);
% Get the masked image
maskedImage = grayImage; % Initialize
maskedImage(~mask) = 0; % Blacken outside skull
% Display the image.
axes(handles.axes2);
imshow(maskedImage,[]);
a=maskedImage;

I am facing an error in the last line: "Undefined function or variable 'a'". So how to fix it so that I assign the value of maskedimage in variable "a" and I also want to pass the value of a using handles structure. How to do it? I am attaching my complete code. Please Sir have look at it.

Answer 1

[Image Analyst]

Remember that all variables are local, unless you do special things to make them global, like detailed here: http://matlab.wikia.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.28s.29.3F

So in your SKULL_Callback, you immediately start using the (poorly named) local variable "a" without ever defining it or bringing it in from some other function. Read the FAQ to see how you can access an "a" that you created in some other function, for example by doing this in both functions:

global a;