Re: CAPTCHA image validation in web form

["Raul A. Jager W." <raul@xxxxxxxxxx>]

I have found (long ago, I don't remember where) a java program that 
generates the images, try Google...

vhamberg@xxxxxxxxxxx wrote:

> I've been thinking about native image generation as this thread continures. Seems one could generate oddly placed numbers into a spooled file using the various font characteristics and rotation, then run the result through HPT or InfoPrint Server to get a graphic image - we have a couple converter products that could help in the effort, but this is not specifically a vendor plug.
>
> There are also a TIFF library and a PNG library of functions that can be installed into PASE. Maybe these have some uses in such a process.
>
> Eh?
>
> Vern
>
> -------------- Original message -------------- 
> From: Ralph Daugherty <rdjfc@xxxxxxxxxxxxx> 
>
>  
>
> > There was a slashdot thread or two on CAPTCHA's a few weeks ago, but 
> > no one really offered anything very helpful about what is going on out 
> > there. 
> >
> > Lots of quibling over how certain MSFT entities practice it in a 
> > substandard way, but for the most part that's just /. being /. However, 
> > when I looked at the example CAPTCHA images, they were trivially 
> > straightfoward letters for OCR'ing, relatively lined up and well separated. 
> >
> > Displaying in different colors including pastels really screws OCR 
> > up, but it's not necessary. The key is to overlap the characters 
> > somewhat with characters tossed and turned. 
> >
> > I agree with the suggestion to just generate these images with 
> > random number of characters (from three to five, for example) generated 
> > at positions that overlap at least two of the characters and store a set 
> > of them on IFS with answers in a file keyed by the file name as 
> > suggested (by Nathan I think). 
> >
> > My vague understanding from lots of /. references is an implication 
> > that CAPTCHA's are forwarded to very, very low paid people assisting URL 
> > spammers (not necessarily worded that way elsewhere, my description) to 
> > reply to the CAPTCA's. Given that most spamming attempts come from bot 
> > networks of random owned PO's, and that responses are fairly quick, it 
> > is onconcievable to me that OCR software algorithms have been downloaded 
> > to owned bot PC's or that the CAPTCHA images are forwarded and OCR'd 
> > elsewhere. 
> >
> > In any event, as I suggest here to do, most CAPTCHA's are not 
> > OCR'able anyway due to overlapping and/or very difficult to separate 
> > from background characters. 
> >
> > Nathan's suggestion is really quite simple and the way to go. 
> >
> > rd 
> >