gray level cooccurrence matrix

my matrix is

a=[1 1 5 6 8;

   2 3 5 7 1;

   4 5 7 1 2;

   8 5 1 2 5];
i apply the function *graycomatrix(a)* ;my out put is 8*8 matrix pixel(8,8)=16 and all other values are zero;
but i want  to obtain following matrix.

[1 2 0 0 1 0 0 0;

0 0 1 0 1 0 0 0;

0 0 0 0 1 0 0 0;

1 0 0 0 0 1 2 0 ;

0 0 0 0 0 0 0 1;

2 0 0 0 0 0 0 0;

0 0 0 0 1 0 0 0];
when i'm applying *graycomatrix(mat2gray(a))* ;it gives the correct out put.what is the difference between these two.

Answer 1

[Image Analyst]

The default is to bin gray levels into 32 gray level wide bins. You can override that and have 256 bins if you want - it's one of the input options.