MATLAB: 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',...
X = imread([pathname,filename]);
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);
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?

Best Answer

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.