while executing my code there is no error but i did not get any output

while performing cross correlation i get white screen as my output.can anyone please tell me whats my mistake in my code,because i m a new matlab user.I am attaching my code for your kind reference..your help is really appreciated

clc;

clear all;

close all;

a=(im2double(imread('bookshelf.jpg')));

a=imresize(a,[255 255]);

figure();

subplot(2,2,1);

imshow(a);

b=rgb2gray(a);

% r =a(:,:,1);

% g =a(:,:,2);

% b =a(:,:,3);

% d=0.33*(a(:,:,1)+a(:,:,2)+a(:,:,3));

subplot(2,2,2);

imshow(b);

% gaussian kernel

N = 5; %// Define size of Gaussian mask

sigma =2; %// Define sigma here

%// Generate Gaussian mask

ind = -floor(N/2) : floor(N/2);

[X Y] = meshgrid(ind, ind);

h = exp(-(X.^2 + Y.^2) / (2*sigma*sigma));

h = h / sum(h(:));

%// Convert filter into a column vector

h = h(:);

%// Filter our image

I_pad = padarray(b, [floor(N/2) floor(N/2)]);

C = im2col(I_pad, [N N], 'sliding');

C_filter = sum(bsxfun(@times, C, h), 1);

out = col2im(C_filter, [N N], size(I_pad), 'sliding');

subplot(2,2,3);

imshow(out);

out=out(:);

b=b(:);

l_p=xcorr(b,out);

subplot(2,2,4);

imshow(l_p);

Answer 1

[Subhadeep Koley]

You are not getting any output because you are trying to display the vector l_p as an image. It seems you are trying to 2-D calculate the cross-correlation between b & out. Therefore, using xcorr2 instead of xcorr might help. Refer the code below.

clc; close all;
a = im2double(imread('peppers.png'));
a = imresize(a, [255, 255]);
figure; subplot(2, 2, 1); imshow(a, []);
b = rgb2gray(a);
subplot(2, 2, 2); imshow(b, []);

% gaussian kernel
N = 5; %// Define size of Gaussian mask
sigma =2; %// Define sigma here

% Generate Gaussian mask
ind = -floor(N/2) : floor(N/2);
[X, Y] = meshgrid(ind, ind);
h = exp(-(X.^2 + Y.^2) / (2*sigma*sigma));
h = h / sum(h(:));

% Convert filter into a column vector
h = h(:);

% Filter our image
I_pad = padarray(b, [floor(N/2) floor(N/2)]);
C = im2col(I_pad, [N, N], 'sliding');
C_filter = sum(bsxfun(@times, C, h), 1);
out = col2im(C_filter, [N, N], size(I_pad), 'sliding');
subplot(2, 2, 3); imshow(out, []);
l_p = xcorr2(b, out);
subplot(2, 2, 4); imshow(l_p, []);

[deep k]

thank you so much for ur help.