Tuesday, March 27, 2007

SLO 1.1.5

The last changes to Scanning Large Objects are from 2006-12-18, but it seems that I managed not to publish these changes for quite a lot of time now... More than 7 months.

An excerpt from the changelog:

As of 060803, I have decided to convert this to TeX and make a
very brief history of this document\ldots
060803 - Conversion to LaTeX, enough changes to promote to 1.1
061212 - Finally came back to this article. Added the screenshot that
was in my weblog, changed the title (added version number to it),
fixed some parts that didn't sound quite right for me, promoted
version to 1.1.5 (It is pretty tricky to decide on version number ;) )
070106 - Fixed some typos, prepared this to be published (in several formats)

The article, in various formats:

Saturday, September 16, 2006

Rsync on Windows

When several computers are networked together, you can take advantage from this - you can setup rsync to synchronize data between computers. This can be particularly useful when you want to sync laptop with desktop

Note: Maybe this tutorial is over-verbose, but i'm used to assume nothing from the _user_.

I'll be talking about Rsync usage in Windows... Although i am currently writing this in Vim editor under Linux.

After you have them installed, follow the following steps:

First, you have to install both cwRsync packages from here . After you have them installed, modify the batch source below to suit your needs. :)
Don't worry, the batch file example is reasonably commented and places that have to be changed are marked by "CHANGE HERE" lines

-------Start Batch example-------

:: This is first to suppress command themselves echoing to the screen

:: Make environment variable changes local to this batch file

:: This command specifies directory cwRsync is installed to
:: Specify different path if different from default

:: Set CYGWIN variable to 'nontsec'. That makes sure that permissions
:: on your windows machine are not updated as a side effect of cygwin
:: operations.
SET CYGWIN=nontsec

:: Set HOME variable to your windows home directory. That makes sure
:: that ssh command creates known_hosts in a directory you have access.

:: Make cwRsync home as a part of system PATH to find required DLLs

:: Example : C:\WORK\* --> /cygdrive/c/work/*
:: Example 1 - rsync recursively to a unix server with an openssh server :
:: rsync -r /cygdrive/c/work/ remotehost:/home/user/work/
:: Example 2 - Local rsync recursively
:: rsync -r /cygdrive/c/work/ /cygdrive/d/work/doc/

:: Simple menu for choosing synchronization direction

:: You are free to change the computer's name from Foo to something more sensible
:: Do one search and replace run on this menu.
echo 1. Retrieve Wiki from Foo
echo 2. Send Wiki to Foo
CHOICE /C:12 /N Make your choice:

:: You must replace paths, IP adresses and usernames
:: An explanation for the clueless:
:: Replace user with user which was defined in secrets file
:: Replace IP with, well, Foo's IP adress
:: Replace path with your path
:: Note about cygwin's path: It consists from /cygdrive/x/Path
:: where x is your drive's letter, eg C drive
:: Another thing to note about UNIX paths in general
:: is that they use forward slashes, not backslashes
:: EG, C:\Windows\system32 in this format would be /cygdrive/WINDOWS/system32
:: Yet another difference is that path names are CASE SENSITIVE,
:: Meaning that Doc, doC and doc are three different filenames


rsync --del --progress -av "/cygdrive/c/Place/That/Needs/To/Be/in/sync/" user@


rsync --del --progress -av user@ "/cygdrive/c/Place/That/Needs/To/Be/in/sync/"

:: Here are the explanations of command line flags
:: used (taken from manual of course :):
:: -a, --archive archive mode; same as -rlptgoD (no -H)
:: --del an alias for --delete-during
:: --delete-during receiver deletes during xfer, not before
:: -v, --verbose increase verbosity
:: --progress show progress during transfer

echo -----------------
echo I hope the sync was succesful! :-)

-------End Batch example-------

When you're done with that batch file, you should save it as C:\Program Files\cwRsync\sync.bat and you're done with the client part...

The daemon (server, service) part needs two files for configuration:

rsyncd.conf and rsync.scrt

The first file contains configuration, folders for sync et cetera.

Rsyncd.scrt contains plaintext pairs of usernames/passwords. You can name rsync.scrt whatever you want to, as long as you don't forget to update pointer in rsyncd.conf.

-------Start rsyncd.conf example-------

use chroot = false
strict modes = false
hosts allow = *
log file = rsyncd.log
pid file = rsyncd.pid
secrets file = rsync.scrt

path = /cygdrive/c/The Place/Docs
read only = false
auth users = user
transfer logging = yes

-------End rsyncd.conf example-------

-------Start rsyncd.scrt example-------


-------End rsyncd.scrt example-------

These configuration files must be unique for both hosts. I.e., 1 host must target 2nd host in batch file, et cetera.

When all of the configuration is done and config files are in place... start the daemon:


sc config RsyncServer start= auto
net start RsyncServer

(Enter this to cmd prompt...)
(no, the weird space in "start= auto" is NOT a typo. That's actually correct syntax... Duh)

Or, if you prefer the tedious rodent-GUI way:

Go to Start>Settings>Control Panel>Administrative tools>Services, find RsyncServer, go to properties, make startup type automatic, start it.

When finished, launch that "sync.bat" or whatever you have named it, and it should give you a proper mini-menu for choosing synchronising direction. Enter the choice number, and the synchronisation shall commence... Happy synching :-)

Edit (2006-09-20): Sorry, the "choice" command isn't included in Win2k/XP by default; It is part of Microsoft's NT Resource kit... Choice.exe can be downloaded from here. Put it to C:\(Windows|WinNT)\system32 or to directory where is that rsync script located (folder where CwRsync is installed)

Thursday, September 07, 2006

Mysteriously unreachable websites

Today i solved a great annoyance i had for a loooong time... I couldn't access quite many websites:

www.ubuntu.com (No, i am NOT an ubuntu user. It is just that that i couldn't reach their website)

and a whole lot of other domains. I have regarded it as mystery and blamed ISP for that... Until today.

Today, i decided to look at them more closely and my quest was to find similarities between these hosts.

The whole log of how did i diagnose and fix it (maybe oververbose as always):

#This is my router box running Slack10.2
#First, i tried to nslookup and then follow the packets
root@EN6350:/var/log# nslookup python.org

Non-authoritative answer:
Name: python.org
root@EN6350:/var/log# traceroute python.org
traceroute to python.org (, 30 hops max, 38 byte packets
1 ( 2990.280 ms !H 2993.109 ms !H 2999.948 ms !H
root@EN6350:/var/log# traceroute
traceroute to (, 30 hops max, 38 byte packets
1 ( 2995.091 ms !H 2990.231 ms !H 2999.924 ms !H
#This is fake /|\, my gateway's ip is different
#nslookuping once again, to see possible similarities
root@EN6350:/var/log# nslookup lilypond.org

Non-authoritative answer:
Name: lilypond.org
root@EN6350:/var/log# nslookup ubuntuforums.org

Non-authoritative answer:
Name: ubuntuforums.org
root@EN6350:/var/log# nslookup ubuntu.com

Non-authoritative answer:
Name: ubuntu.com
#So, strangely, all of nonreachable hosts are in netmask.
#Let's look at route and iptables
root@EN6350:/var/log# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface * U 0 0 0 eth0 * U 0 0 0 eth1
loopback * U 0 0 0 lo
default UG 1 0 0 eth1
# route causes all packets sent to some ip address which starts with 82, be sent to null
#So i will delete that route.
root@EN6350:/var/log# route del -net netmask dev eth1
#Now, let's try tracerouting packets
karolis@EN6350:~$ traceroute python.org
traceroute to python.org (, 30 hops max, 38 byte packets
1 c01.int.balticum.lt ( 8.700 ms 10.213 ms 9.128 ms
2 c02.int.balticum.lt ( 62.339 ms 40.145 ms 9.255 ms
3 e01.int.balticum.lt ( 10.151 ms 10.296 ms 9.614 ms
4 ( 13.482 ms 12.103 ms 14.310 ms
5 ( 232.569 ms 237.165 ms 159.932 ms
6 s6-0-0.11-8-0.ar4.DEN2.gblx.net ( 196.053 ms 362.947 ms *
7 so1-0-0-2488M.ar1.AMS1.gblx.net ( 285.953 ms 361.452 ms 242.792 ms
8 * XS4ALL.so-7-0-0.nar1.AMS1.gblx.net ( 484.540 ms 282.054 ms
9 0.so-6-0-0.xr1.3d12.xs4all.net ( 249.593 ms 141.258 ms 261.868 ms
10 0.so-3-0-0.cr1.3d12.xs4all.net ( 356.662 ms 210.328 ms 298.223 ms
11 dinsdale.python.org ( 91.372 ms 290.529 ms 276.604 ms

So i solved this problem only after about a year since it appeared... Because I couldn't imagine why those sites wouldn't work. But it's better later than never, I guess

Wednesday, May 31, 2006

Lithuanian HOWTO for Zenwalk Linux

The following is a log of changes you need to do to configuration files to get Lithuanian keyboard layout. It should work for any GNU/Linux distribution that uses Slackware-style pathnames and startup scripts/their locations.

Open /etc/X11/xorg.conf, find Section "Input Device" , and something like Identifier "Keyboard0" or Identifier "Generic Keyboard" . Changes you need to make to this section:

Option "XkbRules" "xorg"
Option "XkbModel" "pc105"
Option "XkbLayout" "us,lt"
Option "XkbVariant" "extended"
Option "XkbOptions" "grp:alt_shift_toggle"

Add the following line to /etc/profile.d/lang.sh:
export LC_CTYPE="lt_LT.utf8"

You can find an applet for switching keyboard layouts visually for Xfce here . Install it via installpkg and add to Xfce menu.

Friday, April 21, 2006


Recently, i have done one project: I scanned one large map (one of those which are meant to be hung on a wall for the whole class to see). Because i had problems with the technique myself, and because i couldn't find any information about this on the internet myself, i have decided to share this information for all the Net to see...

This tutorial was written for user who understands general terms in graphics and is willing to experiment with the parameters which are different to eachproject. It tries to guide through the process of joining/stitching of about 60-80 indvidual scans/pieces/parts. If you only try to stitch A3/A2 using your A4 scanner, you have to follow only steps 3 and 7

The main problem is software: i couldn't find a decent program for stitching scanned image because they don't find the correct keypoints between the images, meaning that they cannot find similarities in overlapped areas of the images, and subsequently meaning that the program cannot join the images. Realviz Stitcher, a well known program, really dissapointed me with it's one limitation: "Every image must be the same size". Because of that, scanned images i have straightened (straightening changes dimensions of resulting image) couldn't be stitched at all (it even refuses to read them when it sees this darn difference) even when they differ only in one pixel! And it is said that this program is optimized for stitching scanned images...

After all this search for programs, i gave up. I now tried to configure my primary stitching program - Autostitch... It worked, but i spent really much time configuring it to work correctly. Now all the following stuff seems basic to me, but i know that absolute majority of people don't even know how is it possible to scan objects of such size, and how you can do that with standard A4 scanner. This process can be broken to 7 parts:

1. Scan the whole thing in overlapping rows (really preferably saving each row in a separate directory eg. Row1, Row2)
2. Download AutoStitch from here
3. Batch process 1 row (convert TIFFs to JPEGs, and rotate them 90ยบ to left)***
4. Configure Autostitch to these parameters: screenshot and feed the 1st row source images to Autostitch for stitching. It will be saved as pano.jpg at the directory where pictures are located
5. Repeat third and fourth steps until rows are depleted. Use the same Autostitch configuration for each row
6. Batch rename all of pano.jpg's (batch processing is preferred because it is really boring work to rename them one by one with mouse and keyboard) to DSC01.jpg, DSC02.jpg (or something like that) and move them to a directory called "rows"
7. Now, select the contents of the folder "rows" and stitch them (it will refuse to do that if you didn't rename pano.jpg's and left them pano.jpg, pano2.jpg). See note about parameters if problems occur.

*** I assume you scan in vertical pieces (text flow like in normal portrait A4 paper)


Scaling usually does not matter when you're joining only some images; but you'll probably have to adjust it when doing the final stitch. SIFT image size is sometimes useful to adjust for precision; But usually you can leave it intact

note about parameters: autostitch is a bit tricky to setup: you have to keep track of almost every parameter. Because of that, i have included screenshot(s) of preferences window. An item worth noting is size: if you use a value too high, you may end up with an error message "out of memory" or, more likely, with unfinished output image. "Out of memory" is most likely to occur when you're doing the step 7. That means you'll have to precisely set the output size so that it isn't too big.

note about performance: to do all this with really large maps, you'll need at least 256MB of RAM in your computer (really minimum for such images). I used 1GB for this project, but 512MB is acceptable too.

Wednesday, April 05, 2006


This post was posted nearly year ago in a place that doesn't exist anymore. But it is pretty interesting (i was really an apprentice of networking back then), although short. So...

2005-06-27 13:07

Well, i have been learning about networking lately. About things required to set up LAN and to connect Windows XP to Windows for Workgroups 3.11 particularly. There seems to be many of websites about this kind of network, and many sites about DOS and Windows 3.1/3.11 generally... So fun to return where all my computer computer experience started: DOS, Norton Commander, Windows 3.x! When i look at all the old programs, games, i wonder: why isn't today's software so fun, nice and recource-efficient than in old times? Most of today's software is bloated, takes up much space, has hundreds of totally unnecessary features, tries to be smarter than computer user (last two features are especially true about modern MS Office)... For example, let's look at screensavers. 3D? Millions of colours? Do these things really matter? They don't add much to fun factor anyway. For example, the best screensaver of all times is "Johnny Castaway" which was released in 1993. Twelwe years ago. Yet you can watch it for HOURS! There even is a fan site about him, which i have discovered 5 mins ago :) http://web.onetel.net.uk/~gnudawn/johnny/

P.S. I'd like to add some comments: "Johnny Castaway" is an animated screensaver, which is like cartoon: you can watch it for hours, because there is an infinite amount of variations of events. By the way, don't read everything about the events in that site: it's a spoiler :-)

Thursday, March 30, 2006



It is a nice little program from Micro$oft which shows information you probaly didn't know your computer logs. It shows you current system uptime or a log of nearly every boot and shutdown of your PC. It is really interesting to launch on a computer to see how the PC is used :-)

I don't know what more could i say about this little utility. When started without parameters, it displays you current system uptime (for how much time has it been running). With /s switch it will show you key system events (boots and shutdowns) and time between shutdowns and boots, which means it will show you downtime and uptime of the box.

The usage:

Uptime [server] [/s ] [/a] [/d:mm/dd/yyyy | /p:n] [/heartbeat] [/? | /help]

server Name or IP address of remote server to process.
/s Display key system events and statistics.
/a Display application failure events (assumes /s).
/d: Only calculate for events after mm/dd/yyyy.
/p: Only calculate for events in the previous n days.
/heartbeat Turn on/off the system's heartbeat
/? Basic usage.
/help Additional usage information.