i have a code that stack the 2d images into 3d array and save in volume.fib and its output is good but when i'm trying to put into function it show some error ?

numberOfSlices=186;
image = zeros(215,256,numberOfSlices);
for slice = 1 : numberOfSlices
  dir_name='E:\BTN-7\final year project\regionbased_seg\complete project/edgedetection/prewitt';
  thisSlice = double(imread(strcat(dir_name,num2str(slice),'.png')))/255;
  image(:,:,slice) = thisSlice;
end
dimension = size(image);
image = reshape(image,dimension);
image = image(:,:,1:2:dimension(3));
image = image(:,1:2:dimension(2),:);
image = image(1:2:dimension(1),:,:);
dimension = size(image);
image = reshape(image,1,[]);
save wow.fib -v4

• this is the code that is good and give correct output but*

function visulazition_Callback(hObject, eventdata, handles)
numberOfSlices=186;
image = zeros(215,256,numberOfSlices);
for slice = 1 : numberOfSlices
  dir_name='E:\BTN-7\final year project\regionbased_seg\complete project/edgedetection/prewitt';
  thisSlice = double(imread(strcat(dir_name,num2str(slice),'.png')))/255;
  image(:,:,slice) = thisSlice;
end
dimension = size(image);
image = reshape(image,dimension);
image = image(:,:,1:2:dimension(3));
image = image(:,1:2:dimension(2),:);
image = image(1:2:dimension(1),:,:);
dimension = size(image);
image = reshape(image,1,[]);
save wow.fib -v4

This code when into function give me error at

dimension = size(image);
image = reshape(image,1,[]);

*warning message (these variables might be unused)
and output is not correctly save??*