Update:
For those who read the question as "As a webmaster, what can I use as a text based alternative to CAPTCHA?" please read my original answer -- however it seems that the OP actually meant "As a user, how can I convert CAPTCHA images to a text representation?".
To answer the later, I'd say that this is not really feasible with ASCII art, unless you were willing to use the entire screen, since you'd need this kind of "resolution". If it's a website that people commonly browse using lynx
, then you could contact the webmaster and ask them to solve the problem ;-) -- I was going to suggest wget
ing the image and using an ASCII art generator, but then I realised that it'd most likely change each time it's downloaded.
Original answer:
Ask the user a simple math question; what is 1 + 2? This will protect you against generic spam bots (of which there are many), but not targeted attacks (of which there are few). However, ASCII art would be a much cooler solution.
1The resolution needed to correctly interpret many of today's non-broken captchas would likely more than fill your screen when rendered in ASCII. – eleven81 – 2010-01-11T18:55:39.400
Scrolling would still work. And sitting waaay back from the monitor. – stone – 2010-01-11T19:00:30.950
6Sounds like an excuse to build that 9-monitor PC I've always wanted. – Phoshi – 2010-01-11T19:10:48.980
Next thing you know they'll come up with colored captchas. – mtone – 2010-01-11T19:17:53.677
1For what purpose do you wish to circumvent a captcha ? Something like human recognizion on SO, or download from hosting, or ... ? – Rook – 2010-01-12T00:28:39.127
2@monotone - Can't wait ! :) "What colour is this text ?" ... you: "uhmm, #FF8080 ?" – Rook – 2010-01-12T00:47:30.530
I've seen captchas that say enter the word the letters in red spell out. I've also math problems spelled out "ten minus six". I've seen missing letter captchas "ppl p__" spelling “apple pie” so you enter "aeie". I seen enter the letters in caps. I've seen enter non numbers. I've seen substitution (like replace "x" with "tz" in "abeixot". I'm sure there has to be a way if there is a demand for it. Soon to prove we are human we will have to answer questions like we are playing “Where in the World Is Carmen Sandiego?” (“Enter the name of the city where man first powered, airplane flight?”) – Scott McClenning – 2010-01-12T03:39:49.783
Maybe this should be migrated to doctype.com? – Nick Bolton – 2010-01-12T06:19:35.297
@Nick: Not trying to design a site with a text only capatcha, trying to interpret an image captatcha with text only.
@monotone: Colored ASCII art shouldn't be that much of a challenge, and I have a color terminal. – C. Ross – 2010-01-12T14:29:16.373
1I think you may mean "Captcha" and not "Capatcha" (isn't that a kind of soup?) – Nick Bolton – 2010-01-12T16:40:30.417
1@Nick: you're thinking of "gazpacho". it's really good soup, but more of a summer thing. – quack quixote – 2010-01-17T08:42:59.577
1@ldigas: It's not "circumventing" a captcha, it's normal use. Captchas are there to distinguish between computers and human beings. He is a human being. – Matthew – 2010-01-17T16:51:04.960
@Matthew - I never doubted he was a human being :) But captcha's today can be avoided by certain alhorithms (google: Jdownloader for example, and see it in action ... very nice demonstration) ... so I was wondering what was his goal when asking this question. – Rook – 2010-01-17T17:16:49.567
@~quack Haha, I'm glad someone got my joke! ;) – Nick Bolton – 2010-01-17T18:42:35.890