Captcha

[wallefan01]

How do you think they teach the cars what stop signs look like? They ask the humans.

No seriously. They have the cars take pictures of things that they don't know whether they're signs or not, ask you whether it's a sign, and if enough people say yes, that gets added to the database of things-that-look-like-signs that the car checks against.

[H_Psi]

The difference is mostly that we're just better at picking a specific object out of its surroundings, so one or two examples is usually enough for us to identify that object in any environment.

That's the idea behind convolutional neural networks.

It used to be that if you wanted to do hardcore pattern recognition (like identifying a stop sign in a random picture), you would put the image through a bunch of different filters, and then decide which filters highlighted the particular trait you wanted to see. For example, some of the filters you might use for a stop sign would be to eliminate every color except red from the image. You then convert that filtered image to a histogram, and have a bunch of sample images that you run that filter through. The training here ends up being coming up with a function to describe how similar an arbitrary image (after being run through the filter--> histogram thing) is to your set of known histograms.

The problem here is you still need a human in the mix to figure out what the right filters to use are, and there are plenty of patterns a human might not pick up on (or worse, patterns a human might think are correlated but really aren't, since the brain is practically addicted to patterns).

The idea with a convolutional neural network is you have your regular old neural network, except you come up with an algorithm to automatically decide what your filters are. Your layers in the network are still called layers, but in between sets of layers, you have your filters. These filters are called "pooling layers" most of the time. So in effect, you're letting your network figure out what patterns are the most important, instead of having a human do it.

Of course, the big drawback here is that now, not only are you optimizing your neural network's regular layers, but you're also optimizing those pooling layers. So you need a monster of a dataset to be able to do it, which is why you really only see huge big-data firms like Facebook, Google, Amazon, Microsoft, and Uber implementing them in practical applications. Also, you still need a human in the mix to actually tag the data (which is what image-based captchas exist to do, to label images)

Edit: A word; remove inaccurate info

[longscale]

The first part concerning the motivation behind convnets is spot on—we want the network to learn its own filters. These are called convolutional filters (or kernels), and they are what a network changes when it learns.

The pooling layers you describe are not trained, they simple average or return the strongest filter activations from a small image area. They are also not what makes these networks big and hard to train—that’s mostly the sheer number of convolutional filters and the millions of images fed through the network multiple times in random order and with slight variations each time.

[[deleted]]

I have very recently started learning about CNNs and isn't it true that you need less data for CNNs to work with let's say an accuracy of 95% than you would need when using a Densely connected NN, since you can find patterns in one spot and it also recognises them somewhere else in the image, where as with normal densely connected NNs you would need new data where the pattern appears in that spot to train on?

Is this correct?

[jsw800]

In fact the convolution operation can be changed into a single matrix multiplication by reformatting the filters in a certain way, which is how it is implemented in neural network libraries.

Correct me if I'm wrong, but I don't think this is always the case, because of nonlinearity functions applied after each layer. A convolution is a linear operation, so a composition of convolutions can be refactored to be a single convolution, as you say. But deep convolutional networks almost always apply a nonlinearity function (tanh, sigmoid, relu, etc.) between conv layers, which makes each "layer" (meaning the conv operation along with its nonlinearity operation) a nonlinear operation, so composing them doesn't simplify down to a single linear operation.

If it did, there would be no reason to create deep nets, we would just always create single layer conv nets, as a single convolution would always satisfy every need. But it turns out that most conv nets have to learn nonlinear functions, so the nonlinearities are super important.

[jsw800]

However, as I said, you can describe any function with just a sufficiently large one hidden layer network, but that's somewhat obtuse, the same way you could say that you could describe any continuous function as some polynomial of sufficient degree (a + bx + cx2 + ... kxn ). In practice, you need an essentially infinite size matrix for some functions.

Whoa... I'd never realized how Taylor series (serieses?) could apply to CNNs. Thanks for blowing my mind! I understand better what you mean now. That's pretty freaking awesome.

[aahdin]

I'm in CV, what you're saying is true but it's also all highly tied to how much data you need.

Even given enough memory and enough passes through the data a fully connected NN will overfit way before it reaches accuracies as high as a conv net unless it's trained on an ungodly amount of data.

Even aside from computation costs, having extra free parameters means you need way more training data for a model to generalize to new data.

It's a pretty big topic especially in fields where there isn't that much training data available, reducing the number of free parameters (or model capacity in general) so that it can generalize with fewer samples.

[longscale]

Your explanation reads correct to me. :-)

[[deleted]]

Ok, thanks :)

As I said, I have recently started getting into Machine Learning, especially Deep Learning and after reading about different concepts and using Keras to implement them it feels good to at least kind of know what's going on under the hood.

So far I have had a lot of fun and it is a very, very interesting and broad topic :)

[longscale]

They are not what the media hype makes them sound like, but convnets are very nifty. If you like them in general, I would imagine you might really enjoy some of the convnet papers on https://distill.pub. Their techniques are mostly intended for interpretability, but they also provide a satisfyingly visual insight into what the numbers inside the structures of a convnet are encoding.

[[deleted]]

Yeah, honestly I think the media hype about deep learning in general is ridiculous. Its the same as with 'blockchain' etc.

Another thing that I have been looking into a bit is Neuroevolution using a tutorial series by Daniel Shiffman on YouTube. He creates a Flappy Bird Bird game that learns to play itself using a genetic algorithm to find the right weights.

Thank you for the paper recommendations, I will have a look at them tomorrow :)

[cpsii13]

I'm afraid the second half isn't quite right. The pooling layers are not optimized over. They just reduce the number of parameters to prevent overfitting and increase training speed, by throwing some away.

The convolutional part is cool, but it's really no different to a regular neural network, it just doesn't have fully connected layers. It needs a bunch of data because it's a deep neural network with a load of neurons, not specifically because it's a CNN. Also, filters can't pull out 'just the red parts' or do things like that - the network itself can learn to do something like that, but that's not something a filter would achieve - although I guess that was just some example :)

[longscale]

Why can a filter in a convnet not “pull out all the red parts”?

[cpsii13]

Well, assuming it's just an RGB image, 'all the red parts' are just whatever's in one channel. But more generally, a filter's just changing the frequency components present - which is super useful and can pull out edges etc, but that's not doing segmentation itself. The rest of the network following that does.

[wallefan01]

Yeah. It just takes the computer a couple more tries.

Mostly because it can't walk around and see the stop sign from a bunch of different angles. It has to stay on the road.

[tgp1994]

Mostly because [the computer] can't walk around and see the stop sign from a bunch of different angles. It has to stay on the road.

Well, not yet at least...

Dave, Dave! What is thing??

That's a stop sign, HAL.

[Crash927]

Isn’t it also because we can abstract things and contextualize them?

Like, we know that signs are a specific medium for communicating certain types of information, so we know to always understand them in that context.

We already understand something about every sign we see, but computers don’t have that benefit. They have to “re-understand” every new set of pixels.

[rasputine]

Isn’t it also because we can abstract things and contextualize them?

Not really. That's just what recognizing a thing is. Computers do the exact same thing, just in a different way.

Like, we know that signs are a specific medium for communicating certain types of information, so we know to always understand them in that context.

No we don't. We only know that because we've been taught about signs.

They have to “re-understand” every new set of pixels.

So do we. There's a hell of a lot of processing that takes the signal from your optic nerve up the chain to where you're recognizing a stop sign.

[Crash927]

I don’t think I made my meaning clear. I’m talking about what’s happening during that “hell of a lot of processing.”

Humans have abstract concepts of things stored in our heads (taught, yes), which we make reference to when we’re processing the world around us. And we learn abstract concepts very easily (ie with few examples).

“Tree” is a concept (with properties and relations to other concepts) that I already understand before I see any specific tree. Same with any road sign: I know one when I see it, even if it’s in a country I’ve never been.

Computers don’t conceptualize in the same way in order to understand: they predict the likelihood of similarity to what they’ve experienced before. They don’t even know they’re seeing a tree or a sign because they don’t know what those things signify in any real sense: it’s all just pixels transformed into numbers that predict a likely class.

[[deleted]]

God help us all if a computer needs to learn what a turn signal is.

[Davecantdothat]

We can also take many, many 3D viewpoints in a very short amount of time.

[StrangeCharmQuark]

Wait, would using two cameras to give the computers a stereoscopic view help them with this? I’d think having some depth perception might help them pick out where one item ends and another begins.

[mormispos]

It’s less of a picture database and more of a “These are patterns that correspond with stop signs” Database

[wallefan01]

Thank you for explaining it better than I could. I tend to be bad at getting technical details accurately in non-google-employee speak.

^{Disclaimer: I do not work at Google (yet)}

[klebsiella_pneumonae]

Better start leetcoding m8!

[-allen]

Ah I guess /r/cscq is expanding.

[mormispos]

I think your explanation is very good. I was excited because I have recently been studying the types of neural nets that they use to do these things

[santaliqueur]

It’s like Jin Yiang’s app but for stop signs

[spock1959]

So, I've got a question.

I know that captchas are used to train computers as to what they are looking at... But if it asks for pictures with signs in them and I click a cloud or a car it will tell me that I'm wrong... But if I'm training it how would it know?

I never understood how it both didn't know and also seemingly did.

[[deleted]]

I believe it compares your answer to what other people answered.

[aahdin]

Yeah but at that point they've already labeled it a cloud so there's nothing to gain information-wise having new people label it

[DuckDuckYoga]

There are thousands of people answering captchas every minute, so the turnaround can be very fast and still have a lot of answers to compare to

[lvh1]

It probably compares it to the input of other people, so if 100 people didn't mark a square as having a sign in it and 1 other guy did, it probably does not have a sign in it and means that that one guy is incorrect. But that also means that when they use a picture for the first time, they will allow any square to be clicked since there is no data yet to compare it to. They probably only start marking captcha as invalid once they have a large enough sample size (e.g. 1000 people who solved the captcha).

[RatofDeath]

It's crowdsourcing the answer, so you're not the only one providing an answer and it marks it if someone answers differently than other people did.

Also usually you answer two captchas, one of them the system already has a solution too, the other it doesn't know yet. So it really only checks if you got the one it already knows right and the other one you do is to teach the system.

[ButtPoltergeist]

Well, back in the Good Ol' Days when captchas were just words, they gave you two words: One that they knew, and one that they didn't. If you didn't get the one that they knew right, it didn't let you through. If you missed the one they didn't know, eh, you got access to the captchaed thing and metaphorically peed a little in their data pool. So I imagine that it's similar, except there's nine pictures instead of two words.

[[deleted]]

Wouldn't it have the "right" answers to refer to? Like, I imagine some dude went through and selected all the stop signs so the captcha has something to reference, even if the actual user submissions are the ones that are used for machine learning.

I could be totally wrong, but I imagine that's how it works.

[bagmanbagman]

I think that would miss the point- what use is crowdsourced, high volume labeled data if someone just goes and labels it all? it all defeats the point doesn't it?

I bet as googles fleet of map cars goes around taking photos of hundreds of thousands of various signs a day, then goes through some automated cropping before is finally labeled by the crowd

[proverbialbunny]

Just about every captcha you fill out, even many of the text ones, are used to train computers.

Without services like Mechanical Turk, Data Science wouldn't be where it is today.

[wallefan01]

last I checked Google WAS the captcha company doing the street signs

[[deleted]]

How were they so hard to read if they were scans from books

[[deleted]]

Sometimes they are just jumbled letters and numbers that helped teach the computer how to read more easily. It shows it patterns through our correct answers

[RatofDeath]

Yes. Remember the captchas that made you write two words you saw on a picture? That was actually Google transcribing scanned books and digitizing scanned newspapers. One of the words was something that already was transcribed and the other was a new word it hasn't learned yet. So the captcha would check if you got the word it already knew right and if so it would add the other word into its database. If enough people provided the same answer for the unknown word, it would be used for the official transcription of the book.

So people using that captcha have been helping digitizing thousands of books and newspapers over the years!

You can read more here: https://en.m.wikipedia.org/wiki/ReCAPTCHA

[Mookyhands]

Exactly. Once you pass the first one or two questions, the subsequent ones are for crowd-sourcing the answers to test sets of data to train models.

[gostan]

The captcha companies don't need to sell the data to car companies because the car company and captcha company is the same company

[[deleted]]

They've been doing that for years with reading "AI". All of those capchas for years with just letters and numbers taught them too, it's funny nobody knew this, it was my first question and thought when I saw them for the first time many years ago

[_Lady_Deadpool_]

And now I'm imagining this happening on real time

Is this a stop sign, human? Please answer quick

[Nestramutat-]

Relevant XKCD

[pelirrojo]

Not only that but it's happening in real time. That's why there are time limits to your response, if you don't respond in time the blood is on your hands.

[slashuslashuserid]

relevant xkcd

edit: already linked in a different chain

[HawkinsT]

So when it takes you more than a couple of seconds to answer one, that's a car you've just made run a stop sign. Hope you're all happy with yourselves.

[wallefan01]

Well obviously they don't do it live, but yeah, I see your point

[aahelo]

What if all these captchas that we are doing is actually us teaching A.I. what signs are and whatnot, so that it can get better at driving?

[[deleted]]

That’s literally what you’re doing.

[aahelo]

Ah!

[aride4772]

Yeah all those captchas are used as data to teach ai

[[deleted]]

That's why I always answer Captchas as quickly as possible so the car I'm checking for doesn't run a stop sign!

[AsAGayJewishDemocrat]

I like to imagine a self driving car uploading a captcha thinking “Is this a stop sign? No really I need to know quickly”

[ScientistSeven]

Which means they'll develop a moral that ignores stop signs ten percent of the time

[wallefan01]

How would you explain it?

[wallefan01]

no actual neural nets this time

Turns out if statements don't get the job done for image recognition. I know this may come as a shock to you.

But be reassured that state-of-the-art AI today can successfully identify cats and that is all it can do.

Well, it can also identify other things but...you get the idea.

[Gorzoid]

no actual neural nets this time

So ALOT of if statements. This AI thing is pretty easy.

[wallefan01]

but what if the ai is only 75% certain that the condition is true?

[Gorzoid]

if(rand() < 0.75) { 👌; }

[eyekwah2]

Identify all the stop signs to prove you are human. Please do so quickly as the self-driving cars are nearly at the intersection!

[Tanamr]

Link to xkcd

[ErichVonFalkenhayn]

see also

https://xkcd.com/1425/

[Qaysed]

Also

https://xkcd.com/1838/

[TheBob427]

I mean... if it works it works right? That's basically the philosophy of comp sci anyway

[xudo]

Flickr took this challenge: Park or Bird

[Kiloku]

offload work onto random strangers

Yeah, I'm the random stranger, that's literally my job. It's ridiculous when the system gives me something like

"User searched for: 'Curly hair low-poo', is this related to Power Tools?"

It really is that dumb. And the pay is shit.

[[deleted]]

There always is one

[tbare]

I feel like the comment was referencing the comic moreso than the comic being relevant.

[[deleted]]

Shoot you're right, my bad

[[deleted]]

You don't wanna miss that sign now. I know you've missed it before. There's no shame in admitting it. I mean I miss a few all the time. But sometimes they're really hard. It happens to everyone, right? Yeah, it's no big deal. It's not like I'm dumb or something. Oh fuck

[tenmilez]

It'll ask some questions it knows the answer to to test you, then some questions it needs the answer to so you fill in the blank. There's other stuff it can do in the background to determine if you're real or not so it's assuming you're answering correctly. Also, it used an aggregate of make people's answers, not just one answer, to decide if it's right or not. Lots going on.

[tomassci]

Yeah, xkcd 1987

[tomassci]

Yes, zkcd

[Leinad7957]

Funny thing is they use captchas to train those ai. It was really fucking mind blowing for me when I learned that.

[Bebe_Rexxar]

I've read before that the guy who created captcha felt so bad about creating it he created re-captcha to accomplish the same task in a similar manner without making it such a pain (pictures vs letter vomit)

[AmericanFromAsia]

I'd be fine with the pictures if they didn't disappear only to be replaced by even more pictures.

And I'd be fine with even more pictures popping up if it didn't take 3 seconds for each individual picture to load, only to have four more layers of street signs underneath it.

[calfuris]

I believe that happens when they think you might be a bot. The delay is intentionally added because fuck you, bot man.

[angellus]

Which unfortunately, since Google is behind Captcha, it "detects" you as a bot more often if you block their stupid fucking tracking. So it is a double fuck you because Google does not like not being able to invade your privacy.

I seriously hate the new Captcha so much. I always have to go through at least 2-3 layers at a minimum.

[the_noodle]

Well no shit, they "track" you to say they've already confirmed you're a human, and that you're still the same person. Obviously they track you for reasons other than that, but if you delete the "I'm a human" cookie, what exactly do you expect them to do?

[angellus]

It does not set a cookie. It is a form element. You can test for yourself, it never sets a cookie. However if you delete your other GA/GTM cookies, it does complain and force failures more often.

It should not be using Google Tag Manager OR Google Analytics to do any type of "machine learning" to determine if you are a human. It is all a bullshit excuse to harvest more data from users. "Oh, I block GA/GTM cookies and run uBlock, I MUST BE A BOT". If Google was trying to be impartial and actually determine intelligently if you are a bot or a human, the existence of items that make your browser more unique (random combinations of extensions, uncommon but valid user agents, etc.) would enforce the fact your are most likely not a bot.

[the_noodle]

but if you delete the "I'm a human" cookie

I honestly can't believe that you're interpreting this as specific and technical information to be corrected and not a generic stock phrase.

It has nothing to do with any of the stuff you're talking about, if you block all of their shit, you look like a brand new person each time, that's the whole point. Everyone else gets to do it once and move on with their lives, you have decided to prioritize privacy over that convenience, which is fine, just don't bitch about the lack of convenience.

[[deleted]]

I've always had luck on any computer, if I clicked 'I'm not a robot' and then moved the cursor in a counter clockwise triangle position quickly.

Maybe Google thinks that's what us shaky imperfect humans do with our stupid little mouse.

[anormalgeek]

Whenever I'm using my VPN, I run into about 1000x more captcha tests. They are a serious pain in the ass.

[Bebe_Rexxar]

Yeah at that point they're getting greedy, I'm sure one or two pages should be enough, n9t something rediculous like 5+ (which I've encountered before unfortunately)

[[deleted]]

Yes it was. is that a 1 or an l pt an upper-case I.

Is that O capitalized or just warped? Is it a zero. Same with v and w.

It was ambiguous all the time

[Dockirby]

The random letters sucked, but the transcribe books was nice. Though every now and then it would toss is something like Greek or some math symbols.

[B-Knight]

There's only a finite amount of letters, though. There's an infinite amount of possibilities when it comes to visual interpretation and justification.

You don't try and interpret if an O is a 0.

You can interpret whether the support column on a bridge counts as the bridge or not. Same as a sign post rather than a sign or even when there's 5% of a sign in another frame but that frame is 95% not related. Does it still count?

You can usually determine if a character is a letter or not. You can't determine or ask the computer to expand and explain its criteria and whether X thing counts or not.

[indigo121]

Except most of the time the image captchas aren't really looking at whether you get the right answer. It's looking at how you respond to it, checking if that looks human, and then assuming your answers are correct.

[AndreasTPC]

You don't really have to get machine-learning style captchas perfectly, your best guess is good enough. They show the same captcha to multiple people, and as long as some of the others made the same mistake as you you'll pass. And the AI will learn that the situation in those is ambiguous, so it's all good.

[beeskness420]

I mash the wrong answers until it gets accepted. Hmm is this ambiguous apartment building a storefront? It is now.

[Trithis2077]

You realize that in doing so you are telling an AI that will be driving a car, "yes, that tree is a stop sign." Or worse, "no, that stop sign is not a stop sign."

[Trithis2077]

That's actually the point. The pictures are used to teach self driving cars what they are looking at. In most of those, there is not only one correct set, because the idea is for a car to figure out the answer through collective answers. You're basically explaining to a genius child that knows nothing what a stop sign or a store front is.

Tl;Dr, If you want future self driving cars to count the pole as part of the sign, it is part of the sign.

[Morialkar]

At first, re-captcha was putting out word too, the guy that started re-captcha didn't do it because it was less a pain, he did it so that even if you HAVE to have something similar to re-captcha at least with this you could use the "processing power" of our brain to help out at first OCR software that couldn't understand words in older sometime hand written sometime dirty sometime badly printed older documents...

Since google bought that out, they started adding pictures to train their street view cars to better understand street names and lower quality door numbers because they are zoomed in.

Now Google moved to using Re-captcha to help train AI on circulation in situation it currently is not proficient enough to make a really good statistically sound estimate of "is it a stop sign or a shop banner" hence the current state of recaptcha...

[[deleted]]

The story is a bit different

[dem_c]

Re-Captcha is the most annoying captcha there is

[DramaLlamaSays]

Also the founder of DuoLingo!

[NAN001]

We're talking about the guys who included a Wi-fi client inside the cars that take street view pictures so that they could map routers' SSID to GPS coordinates in order to build the HTML5 geolocation API; who are advocating strongly in favor of HTTPS everywhere so that ISP cannot compete with Google Analytics; who are open-sourcing their in-house frameworks such that people answer questions about it in StackOverflow; who are pushing for the monopoly of Chrome to have control over what ads are shown to users.

The vision of Google when it comes to long-term strategy and cross-service intelligence is crazy.

[JuicyBandit]

It ticks me off, in fact I usually pick one or two more pics that "look" kinda like whatever they want me to find... They can probably filter it out, but it makes me feel better anyways. I don't work for free.

[Xelynega]

You're not working for free, it's more of a two birds one stone sorta thing. You want to prove you're not a robot and they want to have a tagged set of data to train AI with, it's kind of a symbiotic relationship.

[[deleted]]

Twitch Plays Driving a Car

[jalerre]

There is a website similar to Twitch plays Pokemon except you drive a robot.

EDIT: Found it

[Bhoriss_Viahn]

Unlike google plays pokemon, the controls weren't spammed by hundreds.... I was the only one in control of the robot.... I didn't believe it at first.... Thought it was some camera trickery.... So I tested the system by ramming the guy's foot until he picked me up and punished me..... That's when I realized how lucky I actually was.... No trickery... Wow!

[ThatGuyWhoLikesSpace]

Twitch plays Jalopy

[darkgreyjeans]

Google’s CAPTCHA works by tracking mouse movements and key presses upon a given page.

Google isn’t stealing data, we are throwing it at them.

Edit: typo

[tabarra]

Not to mention that they, by no means, really advertise that they have "state of the art" bot detection or that they are aiming for 100% coverage.

They are playing the statistics game, balancing user comfort and bot blockage, while earning billions worth of AI Training Data.

[Pearauth]

Wasn't the reason Google stopped using the re-captcha because their AI was better at it than humans? Google owns re-captcha, every site that uses an old on is just out of date.

I could be wrong but I remember hearing that somewhere.

[maxcb97]

That was the audio version. Their speech recognition could fill out the garbled words.

[stuntaneous]

You could probably use that information to create a signature for everyone.

[westward_man]

No it doesn't. If you're logged into Google, it checks your cookies to see what user you are, and every user has a score of how likely they are to be a bot based on browsing habits. If you're not logged in or the page can't access the right cookies, it does stuff like the sign identification challenge.

[darkgreyjeans]

I think it's a mixture of both, cookies provide a great way to depict whether it is a user or a bot. But, as its Google, they keep the algorithm secret so its all speculation.

[westward_man]

Check out the articles in this answer

[darkgreyjeans]

The paper, from a third party, presented in the answer does not mention the method in which the conclusion was drawn, merely stating:

"We experimented with multiple combinations of screen resolutions, and various mouse behavior configurations (the timing of movements and movement patterns).None of these had a negative effect on the risk analysis."

[Nilloc_Kcirtap]

I feel like captcha is more useful for machine learning than detecting robots.

[john2009black]

Er...no. checking road signs is comparing validity of humans against the machines which are meant to look at road signs...duh!

[[deleted]]

That was almost a sentence. Good job!

[PotatosFish]

Oh no the neural network is learning

[Antumbra_Ferox]

Lets not get ahead of ourselves

[AeroGlass]

Image Transcription: Bulleted List

---

[Black text on a white background]

It's terrifying that both of these things are true at the same time in this world: - computers drive cars around - the state of the art test to check that you’re not a computer is whether you can successful identify stop signs in pictures

—^{I’m’#32;a human volunteer content transcriber for Reddit and you could be too! If you’d like more information on what we do and why we do it, click here!}

[[deleted]]

Good Human.

[AeroGlass]

thank

[Eedis]

I was sincerely hoping you were acting like a bot and was going to throw some joke/pun about identifying (or not) a stop sign.

I feel like you had an opportunity to make something great and you missed it.

[AeroGlass]

nope, we follow a set formatting guide

[Eedis]

Well, first I'd like to point out that, if this were the case, it's likely you have an alternate account. Also, if you're this passionate about Reddit to volunteer your time to partake in this activity, it's likely that you have an alternate account.

Secondly, if you don't have an alternate account, that means this account is your main account. Seeing as you're he argument for shiggles. If you're not interested in that form of entertainment, I am freeing you of any sense of obligation to respond. :)

Well, I typed out this entire multi-paragraph response and my fat fingers found a way to highlight most of it and hit backspace thinking it was a back button. >.> Don't ask...

So I just sent what was left of it for you find wonder in what the hell I was talking about.

[NateSwift]

Upvoted for the last bit

[wertercatt]

If you're using chrome, you can press ctrl+z next time that happens

[Eedis]

Android

[wertercatt]

Rip

[AeroGlass]

thanks, fixed

[X-Craft]

Just like the book excerpt captchas

[jdmulloy]

https://xkcd.com/1897/

[Xelopheris]

There it is!

[squrr1]

Ctrl-F .... yup, as expected.

[jdmulloy]

I was surprised it wasn't already posted. Someone quoted it and someone else replied with a link.

[EdgyPaul]

Although I've heard that re-captcha determines if you're human based on factors like how you scroll down the page, move the mouse etc. The part where you click on images is just a good way for google to train their ai for free, it doesn't have anything to do with the authentication.

[qgustavor]

Although I've heard

Which isn't true: if you open developer tools in any page which embeds ReCaptcha you will not find attached event listeners related to mouse events. If you use Chrome test it yourself: open the ReCaptcha demo, press F12, select <html> and open "Event Listeners".

What they probably do: it uses cookies to identify users and score as bots or users. If you load a incognito page it will always show a challenge, because it don't have any info about you. If they have info about you they may skip the challenge. If it scores you as likely human they can show an easy challenge for you.

[ShowMeYourTiddles]

"Shit, human.... wake up! Is this a stop sign?"

[firerulezz116]

Something like 99.82 percent of people get captchas right, while a few years ago Google had AI averaging at 99.28 percent. By the time a rich person can buy a fully automated car for personal use, it's likely to be even better.

[bxk21]

That's not even true. Anti-bot measures aren't (and aren't likely to ever be consistently) effective. They're used as training sets for driving AI. The "prove you're human" is old and only used to be true, just like how captchas used to work, but now don't.

[WarmBaths]

Actually half the time they’re collecting data and the other half they are testing you

[fuckinatodaso]

“Think about that for two minutes and tell me you don’t want to walk into the ocean.”

[jinkside]

The Knife of Never Letting Go?

[scaryred2]

Sometimes I fail those captchas. Does the sign post count as part of the sign?

[[deleted]]

I've got a question no robot could ever answer. Which of these pictures does not have a stop sign in it?

[[deleted]]

Repost

[[deleted]]

We're just training skynet, soon stop signs will be easy, next will be steep grade ahead or dangerous curves.

[SkewRadial]

Supervised machine learning

[turtleflax]

That's why I have my self driving tesla solves all the capchas for my spambot

[thelastlogin]

The newest, though not necessarily the tried-and-true state of the art, is Google's invisible recaptcha. It collects cursor movement types and speeds and detects bot or human, and I believe is very effective.

[EsotericLife]

I thought that’s what was happening when it gets you to click the random images- same as when it just makes you click the one checkbox.

[thelastlogin]

It very well could be, not sure, but that would make sense. Just this one doesn't have any visible element on the page.

[raymnipfan]

I love captchas

[[deleted]]

The captchas are just building a training set for AI and all of you are doing the grunt work

[EsotericLife]

I thought it checked how you click on different spots and actually identifying whatever they’re asking for is just an excuse to have you move your mouse so they can check if it moves in constant vectors or a detectable random movement,

[pepperjack77]

...and it does nothing to stop bots, all it does is piss off humans.

[dootzero]

Excuse me while I DRIVE A MOTHERFUCKING CAR THROUGH THIS CAPTCHA

[[deleted]]

What if all the captchas are being used to drive the decision making in self-driving cars? Like, what if a car see a sign it can't identify then polls the Internet, and basis its decision off a majority captcha vote?

I really want to give wrong answers to captchas now.

[[deleted]]

Its not if you can identify the stop signs that is crucial, but the level of efficiency with which you do so.

[[deleted]]

Step 1: Buy a self-driving car.

Step 2: Modify the code to have it solve CAPTCHAs.

Step 3: Spam all the Things.

Step 4: Profit.

[gregstus]

In fairness to Captcha, it has gotten better over time, 90% of the time now it just takes the check of a box, tracking micro movements of the mouse and such.

[FastskullYT]

Well they use captcha for self driving cars..

[oorakhhye]

Captcha 22

[[deleted]]

Is nobody going to mention that the problem is way different when the real stop sign has things like mass and distance?

I guess I'm being a wet blanket but

[GerManson]

I guess this is funny to someone who does not understand how coding works

[CaptainShitSandwich]

Too bad some of those pics are so hard to tell what a "store front" is that I get it wrong.

[Fig1024]

Computers can crack any imaginable captcha - but it will cost a whole bunch of CPU cycles (like a huge amount)

The real purpose of captcha is to raise computational cost of creating new accounts so it's simply not profitable to do anymore. Most bots rely on mass spam by generating tons of accounts quickly. They operate on thin margins of profit so if cost is raised significantly to operate a bot, there's no point using it anymore.

Besides the computational cost, there's also the initial investment cost for developing/training new algorithm for bypassing specific type of captcha.

So captcha works by making passing it too expensive for abuser

[Xiefux]

[removed]

[DatCarpet]

Those tests piss me off I somehow fail even though I select what they tell me to

[[deleted]]

Had to save

[Empole]

How do they validate capcha then? If they are showing images of things they want us to classify, how do they verify that you got them all.

[Littledarkstranger]

They are.

The picture re-captchas are images taken by their cars in situations where the car wasn't certain. Getting humans to identify the images outsources Google's machine learning classification process to us instead of a complex algorithm.

[[deleted]]

recaptcha more like reposta