I’m pretty sure this is easier to crack than a CAPTCHA. Still fun idea though :p

Brilliant!

So the colorblind arent allowed to post? While a novel approach, utilizing the recognition of color as a necessary function of your website is a usability no-no.

Just what the internet needs, more methods of locking out people with poor vision.

so hackaday, when will i be forced to review resistor color codes?

hackaday should use a version where you decode DRAM serial numbers. accessible & keeps out the trolls

@VEC7OR very much agreed!

Great so colorblind guys like me can just forget about posting anywhere now?

please ignore my fail remembering my multiplier colors…
47k*

i like resistors.

i like turtles

seriously, you know matching colors is an old trick?

computers don’t have a problem with that.

fail

I unintentionally memorized the resistor color code. I ordered 1500 resistors on eBay and discovered that some were incorrectly labeled. I had to check all of them.

“Great so colorblind guys like me can just forget about posting anywhere now?”

Yea – pretty much! Hopefully this catches on so I don’t have to listen to all of you whiners…

I have a colorblind friend – He says he was taught to know what the colors look like that he can’t see. So he knows when a light is green, although he doesn’t really SEE to green.

This is an awesome idea.

@B1rdm4n some common types of colorblindness don’t work well with standard monitors, various colors look the exact same, but there are ways to adjust the output of monitors to make it more distinct though.
Another problem is that a surprisingly large number of people that are colorblind are actually not aware of it (seriously), they were born with an understanding of color as being how they see it and don’t realize people with normal colorvision see it all different, just like we that can see colors normally have a hard time to imagine how colorblind people actually see things.

@ Engineers with colorblindness,
Is this the reason why I find some projects using nothing but one colored wires?

Also colorblind network engineers, thanks for wiring up our rack mount switches with all yellow cables.

joking aside, nifty CAPTCHA

@supershwa
Well an engineer can just enter the values in his computer, and when prototyping (after testing the circuit on the computer in emulation) get them from the right drawer, plus it’s all SMD now and they aren’t colorcoded bur have unreadable tiny text and are placed by robots.
And when confused you can measure the resistance with a simple meter too.

Colorblind EEs are one thing.

Colorblind Bomb Technicians are an entirely different breed, often referred to as “hamburger”.

Neat but you could just use autohotkey to compare the colorband to the colors available on the slider and click the ones that match. Might be more secure on geeky sites by just asking the resistance of the bands with no sliders.

I think I worked out how to hack this. I got the meaty bits taken care of, but I’m not motivated to glue it together into a script tonight.

I used wget 10 times to get a sample of the resistor images.
I found that the color of the bands were located at the following pixel locations:
45×40
80×40
110×40
150×40

Ran those through ImageMagick like so:
convert png:resistorImage.php.3[1x1+45+40] txt:
convert png:resistorImage.php.3[1x1+80+40] txt:
convert png:resistorImage.php.3[1x1+110+40] txt:
convert png:resistorImage.php.3[1x1+150+40] txt:

That spits out the correct RGB codes like so:
$ convert png:resistorImage.php.3[1x1+45+40] txt:
# ImageMagick pixel enumeration: 1,1,255,rgba
0,0: (100, 50, 0,255) #643200 rgba(100,50,0,1)
$ convert png:resistorImage.php.3[1x1+80+40] txt:
# ImageMagick pixel enumeration: 1,1,255,rgba
0,0: ( 0,255, 0,255) #00FF00 lime
$ convert png:resistorImage.php.3[1x1+110+40] txt:
# ImageMagick pixel enumeration: 1,1,255,rgba
0,0: ( 0, 0,255,255) #0000FF blue
$ convert png:resistorImage.php.3[1x1+150+40] txt:
# ImageMagick pixel enumeration: 1,1,255,rgba

So the outputs are nicely machine readable into RGB values.

From there we have to match the RGB codes to the form, the form values resist1,2,3,4 are set to match the number shown in the slider. These don’t change so we can swipe them once and get the 0-9 values.

Then we actually have to calculate the resistance and populate the hidden ohms and perc values using the code in the JS function getResistance().
resist = parseInt(resist1 + resist2) * Math.pow(10, resist3);

document.getElementById(‘ohms’).value = resist;
document.getElementById(‘perc’).value = resist4;

Now that we have resist1-4, ohms, and perc we can then fill in the standard WP form values and submit our post.

I wonder how it can be made better. Maybe using an actual product image of a resistor, so take a catalouge image of a 47K Ohm resistor and then show that to the user. Rotation of the image and varying the angle or width of the bands.

Its a neat and educational CAPTCHA. I had fun roughing out a script to get around it.

Cross posted at the original site, just for my ego.

@phil – I saw CAPTCHA and immediately thought “anti-spam” and had to see if I could get around it. I certainly did not intend to show any disrespect to your work. It’s a great tool and it’s well coded, at least what I can see on the client side.

I still had fun figuring out how to write a script to solve it.

@Freiheit – it’s cool you were tinkering with it, that’s part of the fun – no worries :)

that said, maybe one day we will make an impossible to crack via machine CAPTCHA – and for that one we’ll issue a challenge.

right now, the bigger challenge is to get more people learning electronics :)

Perhaps take it to the next level. See the bottom of http://lib.mipt.ru/?spage=reg_user

Found via http://duvet-dayz.com/archives/2008/03/19/609/ . I like the Rorschach CAPTCHA. :)

Is the tollerance always 0?!?

There is a colorblind-friendly version available (in beta) for those of you going into hysterics over it.

http://wordpress.org/extend/plugins/resisty/installation/

I’m a tetrachromat and I’m still extremely offended that I’m forced to use monitors and other equipment that only use 3 primary colors when I can see 4. I believe this is extremely damaging to my well-being and everyone should get on fixing this for that unlucky 0.00001% of us who have to deal with your dulled down senses right away.

@ susie B “forced to use monitors and other equipment that only use 3 primary colors when I can see 4. ”

what exactly is the 4th primary colour? as far as i was ever taught there was only three… did you perhaps leave off your sarcasm tag by accident??

I TOTALLY agree, that’s such an awesome idea. No more first posts etc,.

Btw, screw colourblind people, it’s like people with peanut allergies. If you allow people with peanut allergies to “procreate” and make children, they will most likely be allergic to peanuts too. I can only assume this goes the same for colourblind people.

Seriously world wtf, our world is slowly devouring itself because the whole “big dog on top” where natural illness and disease would wipe out people that were not immune to it. Only the strongest survive they say, people used to die from the flu for christ sakes. Now they have a cure for that, so theres no need to build up a resistance to that kind of thing no.

As 5% to 9% of the male population are (knowingly) color-blind, these people are imho not neglectable as an audience.
But if you really want to lock out 5% – 9% of all male internet-users, then just f*cking do it and live with the fact, that you’re gonna have that less visitors.

btw: I’m color-blind too.

I posted the problems and was told I needed to read the code first before I could complain which I had already done. I sent them a detailed description of the problems and explained how trivial it would be to script a spam bot. I know how easy it is because I have a prototype on my site. I have a form with no captcha on my site that will post a comment to their site (with no authentication).

Whereas adafruit is in the top 100k of all internet sites search engines give more weight to links than other sites. Furthermore they are distributing this as a security product which makes them negligent. It looks like they are not using the colorblind friendly version which means they do not care about accessibility.

As a responsible security professional I have notified the vendor (adafruit) and described the problems. If they do not respond I will be compelled to release my code (which I don’t want to do).

@Archeious

>As a responsible security professional

You would know that spam filtering != security?

@Archeious – Freiheit is 100% correct, you cannot post anything on our site unless we approve it most of the time, all depends on what we’re doing each day :) so it really doesn’t matter. we’re also updating our plugin so you’ll likely need to keep up with the changes and features we’re adding… we do not see any emails from you so we’re not sure what type of reply you’re waiting for – responses on HaD aren’t really notifications i think.

@cHRIS
did you not read Susie’s post? She stated “tetrachromat” – it’s a genetic trait that a fraction of the population has (all female) whereby they have four primary colours.

The number of primary colours, btw, being a function of biology… trichromats have receptors in their eyes for 3 colours – red, green and blue. Tetrachromats have receptors for an additional fourth colour.

yes, her post was sarcastic, but yours was ignorant.

@Punkguyta -actually – there are benefits to being colourblind – better monochromatic and low light vision (ie night vision).

@ Nemo – i was actually being genuine in asking what the third colour was, since i didn’t know about that – but thanks for making me sound like a douche.
Also, did you know that the same genes that are connected to hair colour are connected to colourblindness – readheads aren’t colourblind

@cHRIS sorry man, not intending to make you look bad – just pointing out that all the information you needed was in the original post.

It should be clarified that being Tetrachromat doesn’t increase the range of colours that can be seen, but does increase the ability to discern differences between close frequencies.

BTW, I just did a bit of research now – previously I was reporting on half-remembered reports from years ago – and looks like tetrachromancy is still only theoretical, so I bet if Susie B genuinly is, there are researches who would love to speak to her… :)

@Saki_Kawa …actually, the whole purpose of captcha systems *is* to discriminate.

…to discriminate between a real person, and an automated program…

creating something which can make that discrimination without error is exceedingly hard, however.

“learn to respect the others” is great, and when the spammers and other troublemakers online learn that, then we wont need captcha systems at all. I look forward to that day.

Till then, we’re stuck with captcha or similar systems… and many these days offer a listening option for the sight impaired :)