How to turn a picture in dots?

Hello,

I would like to achieve this effect:

…but with a picture. I know that, unlike the example above, I will need dots in different shades of blue to keep some kind of depth in the picture, but I don’t know how to start making something like that the efficient way. I guess I could place every single dot myself, but to cover up a whole face alone, that’s one hell of a job! So any ideas on how to do this in an easier way?

Also, take a look at the “loading content” message of this website. How is this made?

Thanks a lot for your help! :slight_smile:

EDIT: Please take a look at the 4th message in this thread for a better example of what I mean.