Adding Gaussian Random Noise to Image

[rc, cc]=size(ceros);
mu=0;
sigma1=0.12;
noiseGauss=sigma1*rand(rc,cc)+mu;
myphoto=ceros+noiseGauss
subplot(2,2,1);
imshow(myphoto);
title('Gaussian Random Noise with sigma=0.12 of ceros','FontSize',[9]);
subplot(2,2,2);
imhist(myphoto);
title('Histogram of ceros with gaussian random noise sigma(0.12)');

sigma2=0.22;
noiseGauss2=sigma2*rand(rc ,cc)+mu;
myphoto=ceros+noiseGauss2;
subplot(2,2,3);
imshow(myphoto);
title('Gaussian Random Noise with sigma=0.22 of ceros','FontSize',[9]);
subplot(2,2,4);
imhist(myphoto);
title('Histogram of ceros with gaussian random noise (sigma=0.22) ');
% We already know the row and column of ceren_gray which is 120 220
% respectively and mu is the same.


noiseGauss1=sigma1*rand(row ,column)+mu;
mygrayphoto=ceren_gray+noiseGauss1;
subplot(2,2,1);
imshow(mygrayphoto);
title('Gaussian Random Noise with sigma=0.12 of ceren_gray','FontSize',[9])
subplot(2,2,2);
imhist(mygrayphoto);
title('Histogram of ceren_gray with gaussian random noise (sigma=0.12)');

noiseGauss3=sigma2*rand(row, column)+mu;
mygrayphoto=ceren_gray+noiseGauss3;
subplot(2,2,3);
imshow(mygrayphoto);
title('Gaussian Random Noise with sigma=0.22 of ceren_gray','FontSize',[9])
subplot(2,2,4);
imhist(mygrayphoto);
title('Histogram of ceren_gray with gaussian random noise  (sigma=0.22)');