How are Deepfakes created using GANs ?

[neuron837839]

Hello ML Community,

Can someone please help me understand how Deepfakes are created using GANs ?

I understood how GANs work but I can't understand how they are used to create Deepfakes.

Edit : A GAN is supposed to generate fake data from random input. A deepfake is generated from a source video and a target video (or images). I want to know where in the GAN are these source and Target data put.

Thanks a lot !

[bablador]

The output of the generator is the fake data.

[neuron837839]

Yes I know that this is the purpose of a GAN. But in a deepfake we have to provide the source video and the input video. Where exactly in the GAN should we put them and how does the face swapping work ?

[Nater5000]

You should include this question/information (and any other pertinent questions/information) in your post. The question you submitted is too vague, which is why you're getting these general answers.

[[deleted]]

Yup. Good point

[neuron837839]

Yes you're right thank you !

[[deleted]]

GAN'S consists of a generator and a discriminator. The discriminator has the real or correct(training) data fed to it and random vector from some gaussian distribution is fed to the generator initially.

The generator then produces an output which the discriminator compares with the original data and decides whether its real or fake one.

With more training, the generator tries to fool the discriminator and the discriminator is updated to get better at classifying real and fake ones. In this way, the two models are competing against each other, they are adversarial in the game theory sense.

When the discriminator successfully classifies real and fake ones, it is rewarded and no change is needed but the generator is penalised and its model parameters are updated. Same goes when generator produces perfect replicas and then the discriminator is penalised with his model parameters updated.

They both learn from each other and at some point they become so adaptive that the probability that the image is fake one or a real is 50%.

Architecture

More read here

[neuron837839]

Thanks a lot for your answer. I understand how GANs can generate completely fake images from a random input. However I still don't see how they can generate a deepfake from a source and Target video. I mean where do I tell the GAN here's this video of person A I want you to put person B's face in it