Recent comments in /f/MachineLearning

iqisoverrated t1_j6wn72a wrote

>The mere idea of detecting a poker playing bot seems much more complicated than detecting chess bots

It just takes more hands to detect but it's not that hard. You can look at extremely low frequency plays that hit exactly the right frequency where a human would use an always/never approach. If you see such plays in different spots then you can be fairly confident it's a bot

(Just like in chess. A human could make all perfect moves - but after some perfect moves it just becomes very unlikely)

1

pm_me_your_pay_slips OP t1_j6wn43x wrote

That models that memorize better generalize better has been observed in large language models:
https://arxiv.org/pdf/2202.07646.pdf

https://arxiv.org/pdf/2205.10770.pdf

An interesting way to quantify memorization is proposed here, although it will be expensive for a model like SD: https://proceedings.neurips.cc/paper/2021/file/eae15aabaa768ae4a5993a8a4f4fa6e4-Paper.pdf.

Basically: you perform K-fold cross validation and measure how much more likely the image is when included in the training dataset vs when it is not included. For memorized images, the likelihood of the images when not used in the dataset drops to close to zero. Note that they caution against using the nearest neighbour distance to quantify memorization as it is not correlated with the described memorization score.

2

enryu42 t1_j6wme0p wrote

Nice! It is pretty clear that big models memorize some of their training examples, but the ease of extraction is impressive.

I wonder what would be the best mitigation strategies (besides the obvious one of de-duplicating training images). Theoretically sound approaches (like differential privacy) will perhaps cripple the training too much. I wonder if some simple hacks would work: e.g. train the model as-is first, then generate an entirely new training set using the model and synthetic prompts, and train a new model from scratch only on the generated data.

Another aspect of this is on the user experience side. People can reproduce copyrighted images with just pen and paper, but they'll be fully aware of what they're doing in such case. With diffusion models, the danger is, the user can reproduce an existing image without realizing it. Maybe augmenting the various UI's with reverse image search/nearest neighbor lookup would be a good idea? Or computing training set attributions for generated images with something along the lines of tracin.

1

Acceptable-Cress-374 t1_j6wirsd wrote

Not really wanting to contradict you, but how would they do that? The mere idea of detecting a poker playing bot seems much more complicated than detecting chess bots, and they're still having trouble over there. How'd you go about detecting bot play in a game with imperfect information, high variance and a very large decision state?

1

GoofAckYoorsElf t1_j6whme3 wrote

There is no simple answer to that. It clearly depends on the person whose work I use, on the purpose (fair use, inspiration), on the credit that I give, on the way, society benefits from either them clinging to their business model or me being allowed to use their work, on so many different things that there simply is no simple answer.

1

badabummbadabing t1_j6wfsok wrote

Exact likelihoods are what attracted me to normalizing flows once, too. But I soon found them too hard to train to yield any useful likelihoods. The bijectivity constraint (meaning that your 'latent' space is just as large as your data space) seems like too much of a restriction in practice. For my application, switching to variational models and just accepting that I'll only get lower bounds on the likelihood got me further in the end. Diffusion models would be a more 'modern' option in this regard as well.

Are you aware of any applications, where people actually use NFs for likelihoods? I am aware of some research papers, but I'd say that their experiments are too much of a contrived example to convince me that this will ever find its way into an actual application.

3

mongoosefist t1_j6wed0f wrote

When the latent representation is trained, it should learn an accurate representation of the training set, but obviously with some noise because of the regularization that happens by learning the features along with some guassian noise in the latent space.

So by theoretically, I meant that due to the way the VAE is trained, on paper you could prove that you should be able to get an arbitrarily close representation of any training image if you can direct the denoising process in a very specific way. Which is exactly what these people did.

I will say there should be some hand waving involved however, because again even though it should be possible, if you have enough images that are similar enough in the latent space that there is significant overlap between their distributions, it's going to be intractably difficult to recover these 'memorized' images.

2

[deleted] t1_j6wcxc9 wrote

Stolen from whom? This comment you posted doesn’t belong to you. Images you post on Instagram don’t belong to you.

Can you explain your thinking a bit more?

Or are you basically realizing how important SOPA was 7 years later, well into the next AI boom when the horse has very much left the barn?

Perhaps you are young and inexperienced in this domain — or both?

8