I sought out input from a someone who has a good deal of expertise in relation to image cipers and he had the following thoughts.
When I zoom in, this is all I see (1a). It looks like simple anti-aliasing to me, and thus probably isn't a code. Now I have taken a look at what I assume Q posted (FREEDOM_.png) (1b) and the modified one posted to 8ch.net. Both are blown up a bit. The original is on the left, with the double flag image on the right. The one on the left has visible anti-aliasing. It could be a low resolution version of the image. The one on the right also has anti-aliasing, but it looks like it is a higher quality. This leads me to believe that the one on the left (from github.io) is really a thumbnail and the one on the right is closer to the source image. I did some searching online and found a Twitter account. https:// twitter.com/IA_MQ
The image there is a .jpg file, which means it uses lossy compression to make an image. Here's the same section of the flag blown up with the image from Twitter. (1c) Do you see the squares with different colors within? That's because of how a .jpg file saves its colors. People don't notice it much with real photographs, but it is far more obvious when you look at cartoons, line art, and other things where you expect a solid, uniform color.
Here I have inverted the colors and you can also see this noise extending into the stripes. (1d) I've searched the EXIF metadata for clues, examined the file for any textual strings, I've even ran it through "outguess". I just thought about the images of the flag. It appears to be much more of a pattern than anything else. I would be able to simulate this by making the flag image and scaling it just a tiny amount. The antialiasing in the image would turn out to produce similar results to what's seen, assuming you remove the background and the foreground colors after the scaling.
If anything, I would wager there's stenographic information or the image may hold some sort of decoding key instead of an actual message that is represented with symbols made from dots. If you are truly set in using those dots as a code, I would suggest a binary type of cipher, perhaps a Baconian cipher where the positions of the binary bits for each letter are mapped to dots on the image. Or maybe a simple substitution cipher would get you what you need, however it doesn't seem to have that feel for me.
Anyway - that was his take.