TED Talks Daily - How to spot fake AI photos | Hany Farid

Episode Date: July 2, 2025

How do you know if that shocking photo in your feed is real, or just another AI fake? Digital forensics expert Hany Farid explains how he helps journalists, courts and governments find structural errors in AI-generated images, offering four practical tips everyday individuals can use when facing the internet’s war on reality.Want to help shape TED’s shows going forward? Fill out our survey!Learn more about TED Next at ted.com/futureyouFor the Idea Search application, go to ted.com/ideasearch Hosted on Acast. See acast.com/privacy for more information.

You're listening to TED Talks Daily, where we bring you new ideas and conversations to spark your curiosity every day. I'm your host, Elise Hugh. Imagine this. You're looking at a grainy photograph of soldiers who've been taken hostage. Is this photo real or fake? Until recently, this question wouldn't have been difficult to answer, but today it may be the first thing we need to ask.

In this talk, digital forensic scientist, Hany Farid, warns of the fast approaching dangers of generative AI in forever changing our understanding of truth and facts, and says that when it comes to our engagement with technology, we're at a pivotal fork in the road. It all comes down to what choice we will make. Stick around after his talk for a brief Q&A between Hany and Latif Nasser, the co-host of Radio Lab

and a guest curator at TED 2025. And tune into this very feed later today for a special conversation between Hany Farid and me, where we dig into some of the deeper ideas from his talk. Some things just take too long. A meeting that could have been an email, someone explaining crypto, or switching mobile providers. Except with Fizz.

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That's pwc.com to learn more. That's pwc.com. Pwc refers to the PwC network and or one or more of its member firms, each of which is a separate legal entity. This episode is brought to you by TurboTax Canada. Business tax season can feel like learning a whole new language. That's why I was excited to hear about TurboTax Business, a new way for Canadian small business owners to file their own T2 corporate tax returns with help from real experts every step of the way. It's the first product of its kind in Canada. DIY, but not alone. You'll get unlimited access to business tax experts who understand how to help you maximize your credits, stay compliant, and ensure your taxes are done right.

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and you've just received a chilling message on social media. Four of your soldiers have been taken, and if demands are not met in the next 10 minutes, they will be executed. All you have to go on is this grainy photo, and you don't have the time to figure out if four of your soldiers are in fact missing. What's your first move?

If I may be so bold, your first move is to contact somebody like me and my team. I am by training an applied mathematician and computer scientist, and I know that seems like a very strange first call at a moment like this. But I've spent the last 30 years developing technologies to analyze and authenticate digital images and digital videos. Along the way, we've worked with journalists, we've worked with courts, we've worked with governments

on a range of cases, from a damning photo of a cheating spouse, gut-wrenching images of child abuse, A range of cases, from a damning photo of a cheating spouse, gut-wrenching images of child abuse, photographic evidence in a capital murder case and, of course, things that we just can't talk about. It used to be a case would come across my desk once a month, and then it was once a week.

Now? It's almost every day. And the reason for this escalation is a combination of things. One, generative AI. We now have the ability to create images that are almost indistinguishable from reality. Two, social media dominates the world and is largely unregulated

and actively promotes and amplifies lies and conspiracies Social media dominates the world and is largely unregulated and actively promotes and amplifies lies and conspiracies over the truth. And collectively, this means that it's becoming harder and harder to believe anything that we read, see or hear online. I contend that we are in a global war for truth, with profound consequences for individuals, for institutions, for societies and for democracies. And I'd like to spend a little time talking today about what my team and I are doing

to try to return some of that trust to our online world and in turn, our offline world. For 200 years, it seemed reasonable to trust photographs. But even in the mid-1800s, turns out the Victorians had a sense of humor. They manipulated images. Or you could alter history if you fell out of favor with Stalin, for example. You may be airbrushed out of the history books.

But then, in the turn of the millennium, with the rise of digital cameras and photo editing software, it became easier and easier to manipulate reality. And now, with generative AI, anybody can create any image of anything, anywhere at a touch of a button. From four soldiers tied up in a basement to a giraffe trying on a turtleneck sweater.

Audience member laughs It's not fun and games, of course, because generative AI is being used to supercharge past threats and create entirely new ones. The creation of nudes of real women and children used to humiliate or extort them. Fake videos of doctors promoting bogus cures for serious illnesses. A Fortune 500 company losing tens of millions of dollars

because an AI impersonator of their CEO infiltrated a video call. Those threats are real, they are here, and we are all vulnerable. It's useful to understand how generative AI works. Starting with billions of images with a descriptive caption. Each image is degraded until nothing but visual noise is left,

a random array of pixels. And then the AI model learns how to reverse that process by essentially turning that noise back into the original image. And when this process is done not once, not twice, but billions of times on a diverse set of images, the machine has learned how to convert noise into an image that is semantically consistent with anything you type.

And it's incredible. But it is decidedly not how a natural photograph is taken, which is the result of converting light that strikes an electronic sensor into a digital representation. And so one of the first things we like to look at is whether the residual noise in an image looks more like a natural image or an AI-generated image. Those star-like patterns are a telltale sign of generative AI.

Now, for mathematicians and the physicists in the audience, that is the magnitude of the Fourier transform of the noise residual. For everybody else, that detail doesn't matter, but you definitely should have taken more math in college. (*Laughter*) Professors can't help themselves. (*Laughter*) But no forensic technique is perfect.

And so you don't stop after one thing, you keep going. So let's go on to our next one, the vanishing points. If you image parallel lines in the physical world, they will converge to a single point, what's called a vanishing point. A good intuition for that is the railroad tracks. Railroad tracks are obviously parallel. They narrow and recede, as they recede away from me, and intersect at a single vanishing point. This is a phenomenon that artists have known for centuries. Railroad tracks are obviously parallel. They narrow and recede as they recede away from me

and intersect at a single vanishing point. This is a phenomenon that artists have known for centuries. But here's the great thing. AI doesn't know this. Because AI is fundamentally, as I just described, a statistical process. It doesn't understand the physical world, the geometry and the physics. So if we can find physical and geometric anomalies,

we can find evidence of manipulation or generation. Evidence number two. All right, what else can we learn? Surprisingly, shadows have a lot in common with vanishing points. And again, this is a physical phenomena that you expect in natural images, and because AI fundamentally doesn't model the physics and the geometry of the world, it tends to violate these physics.

We now have a very good indication that this image is not authentic. The most important thing I want you to take away from this is that while it may not be easy, it is possible to distinguish what is real from what is fake. I think this image is a bit of a metaphor for how a lot of us feel. We feel like hostages. We don't know what to trust anymore.

We don't know what is real, what is fake. But we don't have to be hostages. We don't have to succumb to the worst human instincts that pollute our online communities. We have agency, and we can effect change. Now, I can't turn you all into digital forensics experts in 10 minutes,

but I can leave you with a few thoughts. One, take comfort in knowing that the tools that I've described and that my team and I are developing are being made available to journalists, to institutions, to the courts, to help them tell what's real and fake, which in turn helps you.

Two, there is an international standard for so-called content credentials that can authenticate content at the point of creation. As these credentials start to roll out, they will help you, the consumer, figure out what is real and what is fake online. And while they won't solve all of our problems, they will absolutely be part of a larger solution. Three, please understand

that social media is not a place to get news and information. (*Applause*) It is a place that Silicon Valley created to steal your time, your attention by delivering you the equivalent of junk food. And like... Thank you. (*Applause*)

And like any bad habit, you should quit. (*Laughter*) And if you can't quit, at least do not let this be your primary source of information, because it is simply too riddled with lies and conspiracies, and now AI's slopped to be even close to being reliable. Four. Understand that when you share false or misleading information,

intentionally or not, you're all part of the problem. Don't be part of the problem. There are serious, smart, hardworking journalists and fact-checkers out there who work every day, because I talk to them every day, to sort out the lies from the truths. Take a breath

before you share information, and don't deceive your friends and your families and your colleagues and further pollute the online information ecosystem. (*Applause*) We're at a fork in the road. One path we can keep doing what we've been doing for 20 years, allowing technology to rip us apart as a society, sowing distrust, hate and tolerance. But we can change paths. We're doing rapid-fire questions. You ready? Ready, set, go. We're doing rapid-fire questions.

Ready, set, go. Ready, set, go. Ready, set, go. Ready, set, go. Ready, set, go. Ready, set, go. Ready, set, go. Ready, set, go.

Ready, set, go. Ready, set, go. Ready, set, go. Ready, set, go. Ready, set, go. Ready, set, go. Ready, set, go. Ready, set, go.

Ready, set, go. Ready, set, go. Ready, set, go. Ready, set, go. We're doing rapid fire questions. You ready? Go. Roughly what percent of images online do you believe to be fake? Depends on the platform. Signal to noise ratio is getting close to one. Stay off of Twitter, stay off of X, and stay off of everything else for that matter. But give me, so what do you think? I would say we're getting close to 50%.

Wow. Can you differentiate between things that have like Instagram or TikTok filters or Photoshop versus fully AI generated images? Yes, but it's becoming increasingly more difficult. Are there any websites a lay person can use to check? No. Whoa. Okay. By the way, this is a secondary problem, which is now people are creating fake things, then going to fake sites to authenticate fake things, and it's all getting very weird. Don't do it. Okay. Last one, most important one.

In CSI crime shows, when they say, enhance, can you do that? Yes. Okay, great. Hany Farid, everybody. That was Hany Farid speaking at TED 2025. If you're curious about TED's curation, find out more at TED.com slash curation guidelines. And that's it for today's show. TED Talks Daily is part of the TED Audio Collective.

This episode was produced and edited by our team, Martha Estefanos, Oliver Friedman, Brian Green, Lucy Little, Alejandra Salazar, and Tonsika Sarmarnivon. It was mixed by Christopher Faisy-Bogan, additional support from Emma Taubner and Daniela Balarezo. I'm Elise Hu. I'll be back tomorrow with a fresh idea for your feed. Thanks for listening.

This episode is sponsored by PWC. AI, climate change, and geopolitical shifts are reconfiguring the global economy. That's why industry leaders turn to PWC to help turn disruption into opportunity. PWC unites expertise and tech so you can outthink, outpace, and outperform. So you can stay ahead. So you can protect what you build. So you can create new value. Visit pwc.com to learn more. That's pwc.com. PWC refers to the PWC network and or one or more of its member firms, each of which is a separate legal entity. This episode is sponsored by Sell-Off Vacations. You know how sometimes a single experience, one moment, one place, can shift your perspective

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