I see a flag. I like flags. Especially the Japanese flags. I don’t specifically care for Japan, but the flag is one of my favourites. I prefer flags with low entropy: so I wrote a script once that ranks the nations flags by entropy so I could quantify my preference. Thanks for letting me infodump a bit.
Edit:
Due to people aski g for it: here is the top ten of my ranking:
“White_field” is just an array that holds zeroes. I use this as a sanity check. Code is on github. I can send DM to whomever is interested. I guess it can also be searched for.
Yes! And weirder that bicolour banded flags are not consistently on top. I suspect some float errors. I just know that using the typical Shannon style does even worse. I might add some filter that calculates a differential or something.
I love that you have multiple people replying to you asking for technical details on how you ranked the flag entropy. This is how you know that you are amongst your people here <3
i’d define it as size of an svg file that represents the flag, since more complex flag -> more fundamental elements (rectangles, circles) needed -> bigger file size -> more entropy.
I tried different definitions and settled on spectral entropy. This one uses fourier transform and (I think) this takes the spacial relation of the pixels into account, as opposed to the more common Shannon definition. I’d like to share it but am not sure on how to do that: were I to use GitHub I would doxx myself.
Btw there is gitlab as github alternative but i think that making another gh account is just better then.
Another solution is making here a spoiler with the code in it
Their previous version was indeed without the coat of arms. Much cooler I think. During that time the Liechtenstein flag was identical, but they (Liechtenstein) changed it upon discovery.
I see a flag. I like flags. Especially the Japanese flags. I don’t specifically care for Japan, but the flag is one of my favourites. I prefer flags with low entropy: so I wrote a script once that ranks the nations flags by entropy so I could quantify my preference. Thanks for letting me infodump a bit.
Edit: Due to people aski g for it: here is the top ten of my ranking:
Nations' flag entropy ranking (n=208). Image source: Wikimedia. 0 white_field -1.439759075204976e-10 1 Indonesia 3.3274441922278752 2 Germany 3.391689777286108 3 South_Ossetia 3.8174437373506778 4 Monaco 3.9718936201427066 5 Poland 3.9719290780440133 6 Austria 4.372592975412404 7 Ukraine 4.405280849871184 8 Hungary 4.4465472496385985 9 Albania 4.6134257669087395 10 Mauritius 4.707109405551959 11 Luxembourg 4.721346585737304Here’s how I defined the entropy value for each flag:
def color_weighted_spectral_entropy(image): b_channel, g_channel, r_channel = cv2.split(image) # Calculate spectral entropy for each channel def channel_spectral_entropy(channel): f_transform = np.fft.fft2(channel) f_shifted = np.fft.fftshift(f_transform) magnitude_spectrum = np.abs(f_shifted) if np.sum(magnitude_spectrum) > 0: normalized = magnitude_spectrum / np.sum(magnitude_spectrum) else: normalized = magnitude_spectrum # Entropy calculation with color channel weighting epsilon = 1e-10 entropy = -np.sum(normalized * np.log2(normalized + epsilon)) return entropy weighted_entropy = ( 0.333 * channel_spectral_entropy(b_channel) + 0.333 * channel_spectral_entropy(g_channel) + 0.333 * channel_spectral_entropy(r_channel) ) return float(weighted_entropy)“White_field” is just an array that holds zeroes. I use this as a sanity check. Code is on github. I can send DM to whomever is interested. I guess it can also be searched for.
I like Kazakhstan’s flag because I think its a nice combination of colors:
Its not very low entropy though, at least not compared to ones like Germany’s or Ukraine’s.
Hmm. It seems weird that any tricolour flags would have different entropies, but I don’t know how you would otherwise do a multichannel entropy.
I was imagining a kolmogorov-esque doodad
Yes! And weirder that bicolour banded flags are not consistently on top. I suspect some float errors. I just know that using the typical Shannon style does even worse. I might add some filter that calculates a differential or something.
Well you gotta share that ranking now…
I owe it to the community. Since I don’t have it anymore I am coding it up again. Allow me some time - it’s weekend and I have family to look after.
And that script. I’m curious how you implemented it.
I love that you have multiple people replying to you asking for technical details on how you ranked the flag entropy. This is how you know that you are amongst your people here <3
How are you defining the entropy of a flag?
Subtracting it’s normalized negentropy from 1
i’d define it as size of an svg file that represents the flag, since more complex flag -> more fundamental elements (rectangles, circles) needed -> bigger file size -> more entropy.
How do you rate entropy? Is the script open source so we can see it?
I tried different definitions and settled on spectral entropy. This one uses fourier transform and (I think) this takes the spacial relation of the pixels into account, as opposed to the more common Shannon definition. I’d like to share it but am not sure on how to do that: were I to use GitHub I would doxx myself.
I see, thank you that’s interessing;
Btw there is gitlab as github alternative but i think that making another gh account is just better then. Another solution is making here a spoiler with the code in it
…and what is the stack ranked result?
That really depends on the algorithm used. Ideally it takes colous and spacial information into account. I’ll keep you posted on the ranking.
I also love flags, flags are so beautiful (except the flag of Haiti, fuck you Haiti with your MS paint looking flag)
Their previous version was indeed without the coat of arms. Much cooler I think. During that time the Liechtenstein flag was identical, but they (Liechtenstein) changed it upon discovery.
What is it about the flag of Japan that you like so much?
Simplicity I suppose. Colour combination. In my opinion if i can draw it from memory it’s a good flag.
Two colors, with a basic shape centered? I guess it’s ok.
“Welcome to fun with flags!”