How move each line in text

Question

In steganography is an interesting way of conveying information. Each line is either raised by a few points or not raised at all. How will cause it to subsequent lines of text have been raised about the 4pt up? Map of lifts should be written as possible to change the data every time.

Line shifting, change interline

example image

Are you saying that you want to encode a message in a document of dummy text by raising certain lines? That sounds cool, possible, and hard. — Matthew Leingang, Apr 19 '13 at 15:35
But you need to provide more details or an example before anybody can help. — Matthew Leingang, Apr 19 '13 at 15:47
http://magazynt3.pl/wp-content/uploads/2008/09/steganografia_-_informacja_dobrze_ukryta-6e-300x151.jpg
the 0 in message and 1 is up or down of line — jak, Apr 19 '13 at 17:49
Is the text broken up into lines manually or is that left to the line-breaking algorithm? — Christoph B., Apr 19 '13 at 18:59
The following might be of interest: How to display only certain lines of a paragraph? The intent there is to perform certain actions (underline, perhaps remove altogether) on certain lines (odd, even or something else) of a paragraph conditionally. So, of course, you could raise/drop it and write something in the margin... — Werner, Apr 19 '13 at 19:24
In similar vein to the question linked by Werner, you could also see Blur the text so it's not readable. There the \lastbox technique is also applied to perform certain operations on the lines of a paragraph. — Gonzalo Medina, Apr 19 '13 at 22:47
It could be interesting to raise just letters. Could be a nice job for LuaTeX and the chickenize package. — Uwe Ziegenhagen, Apr 20 '13 at 04:36

score 9 · Answer 1 · answered Apr 19 '13 at 22:44

This hides the first argument in the second, optimised for lowercase ascii only in the first argument (it offsets the ascii code by that of m so that one half of the alphabet raises a line and the other half lowers it. You can use \ to denote a space.

enter image description here

\documentclass{article}

\def\hide#1#2{%
\setbox1\vbox{}%
\gdef\txt{#1}%
\setbox0\vbox{\hsize5cm \raggedright
#2%
\par
\loop
\unpenalty
\skip0\lastskip\unskip\global\setbox1\vbox{\vskip\skip0\unvbox1}%
\unpenalty
\skip0\lastskip\unskip\global\setbox1\vbox{\vskip\skip0\unvbox1}%
\unpenalty
\setbox0\lastbox
\ifvoid0
\else
\global\setbox1\vbox{%
\dimen0\dp0
\count0=96
\expandafter\getnext\txt{}\relax
\dimen2\dimexpr\count0 sp - 109sp\relax
\kern10000\dimen2
\box0
\kern-10000\dimen2
\kern-\dimen0
\hrule
\kern\dimen0
\unvbox1}%
\repeat
}
\leavevmode\box1
}

\def\getnext#1#2\relax{%
\ifx\\#1\\%
\gdef\txt{}%
\else
\ifx\ #1%
\count0=95
\else
\count0=`#1
\fi
\gdef\txt{#2}%
\fi}




\begin{document}
\Large

\hide{hello}{
\def\a{One two three four five six seven eight nine ten. }
\def\b{\a Red yellow blue green. \a\a One two three. }
\b\b}
\hide{david}{
\def\a{One two three four five six seven eight nine ten. }
\def\b{\a Red yellow blue green. \a\a One two three. }
\b\b}



\end{document}

For those interested in some discussion around this topic and solution, there's some back-and-forth in chat... — Werner, Apr 19 '13 at 22:57
This is little endian? hm... hello have more data inside. Look here http://sticksandstones.kstrom.com/appen.html hello: 01101000 01100101 01101100 01101100 01101111
minimum 35 bits ,70 lines — jak, Apr 20 '13 at 13:20

How move each line in text

1 Answers1