Can you modify the code provided on given link.?

http://www.mathworks.com/matlabcentral/answers/85529-how-to-replace-the-center-pixel-of-a-3x3-window-with-the-min-difference-among-its-surronding-pixels

My question is related with above link.

I want to replace the center pixel of a 3x3 window filter with the average of four neighbour pixels in 3 x 3 neighbourhood.

Can anyone modify code provided on that link..?

[Geoff Hayes]

Nimisha - which four of the 3x3 neighbourhood do you wish to average? The ones at the north, south, east, and west of the centre pixel?

[Nimisha]

Yes,exactly..

Answer 1

[Thorsten]

Just convolve your data with the filter

 F = [0 1 0; 1 0 1; 0 1 0]/4;

You can use imfilter for the convolution.

[Nimisha]

 clear all;clc
 grayImage = imread('Coins.jpg');
 image1 = conv(grayImage, ([0 1 0; 1 0 1; 0 1 0]/4) , 'same');
 imshow(image1)

it shows following error

 Error using conv (line 27)
 A and B must be vectors.
 Error in Question_11_3_c (line 3)
 image1 = conv(grayImage, ([0 1 0; 1 0 1; 0 1 0]/4) , 'same');

How to correct for given problem.?

[Geoff Hayes]

The error message is telling you that your inputs to conv must be vectors. You are passing matrices. Try using conv2 instead.