how to implement a MATLAB function to add Gaussian noise ?

I need to implement a function in Matlab to add Gaussian noise to an image let's say cameraman.tif but without using imnoise

Thanks in advance

Answer 1

[Rick Rosson]

   >> doc randn

Answer 2

[Rick Rosson]

   function y = addWhiteNoise(x,snr)
   %
   %   snr is the signal-to-noise ratio expressed in decibels
   %

       stdev = ... 
       z = stdev*randn(size(x));
       y = x + z;
   end

[mina]

thanks for your help.

but this is what i need to do exactly:-

implement a MATLAB function to add Gaussian noise to the image “Cameraman.tif” and compute the signal-to-noise ratio (SNR)

[Walter Roberson]

Okay, go ahead and do that.

Answer 3

[Rick Rosson]

Hi Mina,

What have you done so far? Please post your code.

Thanks!

Rick