Last modified: Wed Nov 23 08:11:46 MST 2005
Porting StirMark to UNIX
is a program developed
by watermarking researchers, most notably
It is used to alter images in ways which are not objectionable
to most users, but may cause some watermark detectors to fail
to find embedded watermarks.
The source code for this program, and Windows executables,
are provided at the
The following text outlines a procedure which was used
to port this code to LINUX.
The code is very standard, and I have every reason to believe
that this procedure will work for any UN*X-like system
with GNU make.
Get the source distribution from the StirMark WWW site.
My LINUX system has a program called unzip which will
extract files from the provided PK-Zip archive.
If you have, or can get this program on your UNIX use it.
If not, you may wish to unpack the source on a Windows machine,
then FTP the source files back to UNIX in ASCII transfer mode.
If you take the later route, you will be able to skip the
ASCII mode translation steps which follow.
Build JPEG Library
If you already have a version of libjpeg.a from the
JPEG group on your system, feel free to try it.
I think it is highly likely to work.
This code is fairly mature and stable.
If you are using your own library, simply add
-Lyour_libjpeg.a_directory to the linker commands
in the following StirMark make file.
If you wish to build the JPEG source delivered with StirMark,
read the rest of this section.
Go to the directory holding the JPEG library source.
- Get rid of the leading space before /bin/sh in
the configure script. It caused problems for me.
This may not be necessary, but I did it.
Then make this script executable:
chmod +x configure
You may be able to avoid this simply by using
I did not start all over to see if the easier
sh configure method would work.
Converting configure to an executable script worked for me.
- If you expanded the zip archive on UNIX, you will need
to convert Windows-style ASCII to the UNIX standard.
For me it was sufficient to convert all *.c, *.h
and the configure file.
I'm sure there are many standard filters to do that, but
I couldn't find one.
I wrote a simple perl script called
pc2unix to do this.
Given this script, the following csh commands can
be issued to convert the base source code:
foreach f ( `ls *.c *.h` )
cat $f | pc2unix > t
\rm -f $f
mv t $f
- type make
- If you want to run the test, get rid of the extra \r
from the first lines of testing.ppm.
I simply used emacs.
But you will need a fairly professional editor to give you
the ability to remove these non-printing characters without
altering any other bytes in the binary file.
Let me know if vi can handle operations like this.
After fixing this file for UNIX, type make test.
- Install the library if you really want to.
I did not.
The following instructions will link this library in directly
from the JPEG build directory.
If you have not already converted all *.h and
*.c files to UN*X-standard ASCII, please do so
following the procedure outlined above for creating the
create a file called Makefile with the following contents:
OBJ=bench.o image.o quality.o reconstructers.o stirmark.o\
error.o lrattack.o quantise.o resamplers.o transformations.o
cc -L../JPEGLib -o StirMark $(OBJ) -ljpeg -lm
Note that lines must be indented with TAB's and not spaces.
If you are using your existing libjpeg.a, replace
the -L../JPEGLib element above with the directory
containing you jpeg library file.
If you have GNU make, this file should be sufficient.
If you do not have GNU make, you may need to add rules
to create the object files form the source.
Typing make will then create an executable called
StirMark, and you are done.
The StirMark executable can be moved to a position of your choosing,
and should need no support files.