lijing <firstname.lastname@example.org> wrote in message <email@example.com>... > Want to normalize an gray image to zero mean and unit variance, but > now I wonder could a gray image=92 pixel value be negative? I have never > seen. Could you give some explanation? > Thank you for your attention! Thank you for your replay!
I believe the gray pixel alues are between 0 and 1, don't know what happens if you make a value negative