how to find average pixels value from matrix 3*3

hello i have the 3*3 matrix now i want to find the average value of it. the image is in gray color. so how to do same...

Answer 1

[Image Analyst]

For one array:

meanValue = mean2(array3by3);

To do it for every pixel in an entire image:

meanImage = imfilter(grayImage, ones(3)/9);

This produces an output image where every pixel is the average of the 9 pixels at the same location in the input image.

Answer 2

[Youssef Khmou]

try :

 H=mean(M(:));