how to find mean gray level value

function pushbutton1_Callback(hObject, eventdata, handles)
global X;
[filename, pathname] = uigetfile({'*.bmp','All Image Files';...
          '*.*','All Files' },'title',...
          'D:\MRI\DOI');
X = imread([pathname,filename]);
axes(handles.axes1);
imshow(X);
minGL = min(X(:));
maxGL = max(X(:));
meanGL = mean(X(:));
message = sprintf('The min gray level = %d.\nThe max gray level = %d.\nThe mean gray level = %d.', minGL, maxGL,meanGL);
uiwait(helpdlg(message));

I try to find a mean gray level value in GUI. When i run the code it will give this answer:

What wrong with the code?

Answer 1

[Walter Roberson]

You are trying to use an sprintf() %d format to print a non-integer value. When you do that, sprintf() uses %e format instead. If you want to print out in floating point, code a %e or %f or %g format.

Remember that the mean of integral values need not be integral itself. For example the mean of 1 and 2 is not going to be an integer.

[Muhammad Harith Ramli]

Thanks