What does it mean by “Adding Gaussian Noise to a 2D Image”? [duplicate]

As far as I understand,

Suppose, we have a 2D image of pixel resolution 200 x 300. That means, the image has 60000 pixels in it.

Now, we would generate $n$ random values and add those values to $n$ number of random pixels.

Now, my question is, what would make those $n$ values to look like Gaussian Random Values?

What would be the logic that I should use?

marked as duplicate by MBaz, jojek♦, Matt L., Peter K.♦Mar 18 '16 at 12:37

• – MBaz Mar 17 '16 at 21:57
• Please, when you have a question from Gonzalez book, i recommend you to cite this book in you questions. – Darleison Rodrigues Mar 17 '16 at 23:51

• It seems so, if $n$ is the number of pixels. – Laurent Duval Mar 18 '16 at 8:14
• Image has 60000 pixels. Of which, I would add noise to $n$ pixels. That's why I am generating the same number of random-values. Am I right? – user18425 Mar 18 '16 at 9:23