Lucy In The Sky With Briolettes

gfoot · Post by **gfoot** » Thu Feb 12, 2009 1:03 am

Hmm, although the title is a good clue, that was hard to narrow down. How was it generated? The rather repetitive but still rather random hatching patterns disguised the answer pretty well.

It probably didn't help that I was only viewing an 80x20 region at a time with varying stride values, in a text console. The real give-away was trying making it only set pixels where the LSBs were set on all three channels at once. That hid a lot of the image and made it clear there was some data, and that it had a certain factor in its stride.

Post by **adum** » Thu Feb 12, 2009 1:42 am

nice job! i wasn't sure this one would ever be solved =)

teebee · Post by **teebee** » Sat Dec 12, 2009 9:07 pm

Comparing the image to the original one (http://briolettes.com/images/brios_002a.jpg) showed that the LSBs must contain some hidden information. However, it took me a very long time until I could see the first structures using the method described by gfoot.

Tron · Post by **Tron** » Tue Feb 08, 2011 8:41 am

The histogram revealed, that there is information in the /l/east /s/ignificant /b/it. The histogram of a "real" image is not that spiked. I suspected it could be a 1 bit b/w image, but autocorrelation showed a factor of 5, which was a big red herring.

Redford · Post by **Redford** » Sun Apr 14, 2013 9:57 pm

Nice challenge (and a very nice wordplay in the title

)
Although I've solved this challenge, I still don't know what's going on with "The gem is not what you want.". Is it meaningful?
How did you extracted the message? I'm not sure whether I did it properly, because I had a lot of noise in final image and I still don't know why the beginning of LSB bits forms 15-bit pattern (is it only to ensure we are on the right way?).
I solved it by creating an image from LSB with x-size = 205 (screen: http://wstaw.org/h/d969c1a830b/).

Sat Apr 30, 2016 11:51 am

Redford wrote: How did you extracted the message? I'm not sure whether I did it properly

Yeah, me neither. I used Java code to extract the least significant bits from the image. Then I couldn't figure out for a long time how to turn this information into an answer. Finally I tried creating images of differing widths and heights, and eventually that approach came up with an image where I could read the answer - but just barely.

It would be really cool to have a sample solution in the Solved section, provided by the one who created the challenge.