Average Filter and Gaussian noise

Hi!

I need help with my assignment

Remove Gaussian noise using Average Filter from the color image using RGB & HSI model (separately)

So i took an rgb image , split the three channel and added gaussian noise to the original image and the color channels. But i'm strugglin to remove the noise using average filter.

I used the following code but it doesn't work, it keeps returning the same noisy image. Is there any better way to solve this. I just wanna use the average filter on a simple rgb image and remove its noise

%partial code%

redAF = filter2(fspecial('average',3),redChannel);

% Find the noise in the red.
noiseImage = (redChannel == 0 | redChannel == 255);
% Get rid of the noise in the red by replacing with average
noiseFreeRed = redChannel;
noiseFreeRed(noiseImage) = redAF(noiseImage);

subplot(3, 4, 10);
imshow(noiseFreeRed);
title('Restored Red Channel', 'FontSize', fontSize);