Image Enhancement using a Composite Laplacian

% Enhancement using a Composite Laplacian
% Read a grayscale image and compute the Composite Laplacian for enhancimg the image
clear all; close all; clc;
f = imread('bird.gif');
f = im2double(f);
[m n]=size(f);
B =zeros(m,n);
for i=2:m-1
for j=2:n-1
B(i,j) = (5*f(i,j))-(f(i-1,j)+f(i+1,j)+f(i,j-1)+f(i,j+1));
end
end
subplot(1,2,1),imshow(f),title('Original Image');
subplot(1,2,2),imshow(B),title('After Enhangement');