Convert from opencv to matlab codes

This code my OpenCV code blog. I want to convert from this codes to matlab codes but i don't know how to do this. Can you help me please?

% I generated random gaussian noise

I = imread('pears.png');

J = rgb2gray(I);

p3 = 0;

p4 = 0.05;

J = im2double(J);

b = J + sqrt(p4)*randn(size(J))+p3;

imshow(b)

dim = size(I);

[rows, columns, numberOfColorChannels] = size(I);

saltpepper_noise=zeros((m, n));

saltpepper_noise=rand(m,n); #creates a uniform random variable from 0 to 1

for i in range(0,m):

for j in range(0,n):

if saltpepper_noise[i,j]<=0.5:

saltpepper_noise[i,j]=0

else:

saltpepper_noise[i,j]=255

.........................