Entries by Stephan Paukner

The fact that the idea of free software is so contrary to the behavior of Microsoft is exactly reflected by how their respective representatives act in their talks. Here’s a quick video edited by myself from sources I found on YouTube:

It’s totally up to you who you trust.

It was exactly three years ago when I sold my previous car. The months before that sale were such a torture and the sale itself was such a relief that I decided to go on without an automobile for some time. I had been living in a vicious circle: I rarely used the car as it was always broken, and it was always broken as I only used it rarely and had it parked outside in all weathers. And because I actually only needed it rarely in the big city, it wasn’t that hard living without one. However, it really would have been impossible without Doris’ company car that enabled a casual weekend shopping or similar. But furnishing our new home outside the urban area was unthinkable with that small vehicle, what forced us to borrow a car from our families once in a while.

Our demands have changed and the torture is now exactly on the immobile side, what led us to the acquisition of a more spacious vehicle. We broke it down to a Škoda Fabia station wagon, as the Octavia model provides more space than we really need. Although a certain Austrian cabaret artist makes fun of people who buy a Škoda with extra equipment (i.e. those who want to have everything but don’t want to pay for it), we just became such folks. It’ll be a Fabia II Combi Elegance 1.6 with 77 kW in Flamenco red Anthracite gray and will arrive at the beginning of May. The list price was just under €20,000.

I complained about my old notebook being too slow at image processing. As I now run a new machine, it’s time to measure the performance increase:

Old system: 1×1.6 GHz CPU, 1 GB RAM
New system: 8×2.67 GHz CPU (by threads), 6 GB RAM
Test file sizes: 11.2–12.5 MB

Task #1: Render 8 RAW images to PPM in multi-parallel
Command line:

Old system time: 1 min 41.1 sec
Old system mem usage: 1 GB (100%)

New system time: 0 min 04.6 sec
New system mem usage: 2 GB (33%)

→ 22× faster

Task #2: Render 8 RAW images to JPEG in multi-parallel
Command line:

Old system time: 5 min 0.0 sec
Old system mem usage: 1 GB (100%)

New system time: 0 min 18.2 sec
New system mem usage: 2.5 GB (42%)

→ 16.5× faster

Hell yeah!

Debian’s standard kernel 2.6.26 has a little drawback: The coretemp module doesn’t recognize Intel’s Core i7 processor. The sensor chip W83667HG of my Asus P6T Deluxe (LGA 1366 socket) is not yet supported as well. This is a typical symptom when using Linux on too recent hardware. However, if it’s enough for you to read an aggregated CPU temperature instead of eight individual core temperatures, you can force loading the w83627ehf module with

and tune the /etc/sensors3.conf to get rid of false alarms.

Luckily, for the current prerelease 2.6.29-rc6 there’s a very recent bunch of patches available that brings support for W83667HG into the w83627ehf module, whereas coretemp already finds the CPU. Follow this guide on how to compile and install a new kernel the Debian way. A drawback is that source modules from the official Debian repositories might not compile anymore, e.g. the MadWifi modules. You have to get them from the project directly (via SVN). You also need to build a current version of lm-sensors (via SVN) to correctly gather the values from w83627ehf. You could then visualize the values e.g. with gkrellm.

Now have fun stress-testing your system with MPrime.

Update 03/24: It appears that these patches didn’t make it into the final 2.6.29 release.

Update 04/09: The patches went into 2.6.30-rc1.

Because it’s a pain, a short reminder for myself on how to connect a Bluetooth capable cell phone with a Debian box:

1. Install bluez-utils.
2. Read this (German) guide and follow instructions, but ignore the obsolete stuff about the pin helper; today it’s just an entry like passkey “1337”;
3. For whatever reason, hcid doesn’t launch a passkey-agent automatically. For the very first connection, you have to do it by yourself:
1. Get both the passkey-agent.c.gz source and its Makefile from the bluez-utils examples directory and compile it; you’ll need libdbus-1-dev.
2. Launch it as /path/to/passkey-agent 1337 HA:RD:WA:RE:AD:DR and go to a different shell.
4. cat < /dev/rfcomm0 and enter the requested pin on your cell. If nothing special happens, you’re done.

In your cell’s Bluetooth settings you could now permanently authorize your PC. The next cat < /dev/rfcomm0 shouldn’t initiate a pin request anymore.

Two days ago I finished assembling my new workstation and set up a 64-bit Debian ‘lenny’ on it. When I decided to go for Intel Core i7 I wasn’t aware that due to Intel’s Hyperthreading technology each of the four cores is able to handle two threads at once, making it effectively an eight(!)-core system to the OS! Dig this:

I thought that the onboard Intel SATA-RAID controller provided a hardware RAID, but it’s just a software RAID in disguise, so I can well let Linux do the job. Then I had problems setting up WLAN with the Atheros card I built in, but thanks to the MadWifi project I got it running. What else? Yes, Memtest86 v3.5 didn’t boot on Core i7 and/or 6 GB RAM, but Memtest86+ v2.11 did.

I named the new system ‘davinci’, honoring the technological genius Leonardo da Vinci, what is consistent with the weapon-like appearance of the Cooler Master Storm Sniper case.

I proudly list the installed components here:

• CPU: Intel Core i7-920 4×2.67GHz
• RAM: OCZ Platinum 3×2GB DDR3-1600 SDRAM, CL7-7-7-24
• Mainboard: Asus P6T Deluxe, 6×DDR3-1333 slots
• GPU: Zotac GeForce GTX 260 AMP²! Edition, 896MB GDDR3, PCIe 2.0 ×16, 2×DVI
• Harddisks: 2× Western Digital RE3 1TB SATA II, RAID-1
• Optical drive: LG Electronics GH22LS30 SATA, 22×/8×/12× DVD±R/+RW/-RAM
• WLAN: D-Link AirPlusXtremeG DWL-G520, 108Mbit, PCI
• Case: Cooler Master CM Storm Sniper
• Power supply: Cooler Master Silent Pro 700W
• Monitor: Samsung SyncMaster 2693HM 26″ TFT-LCD, 1920×1200, DVI, HDMI, speakers, USB
• Input devices: Logitech Cordless Desktop Wave

Currently I just use Intel’s boxed CPU cooler, so I haven’t done any overclocking yet. I’m having an eye on the Cooler Master V10 that’ll be available by April. With this I aim to overclock the cores to 3.2 GHz for the first time, what I might increase to a maximum of 3.8 GHz one day.

Der ORF hat einen Artikel zur von mir vorgestern erwähnten Ö1-Sendung nachgeworfen, offenbar als Vorschau auf die heutige Sendung „Matrix“ um 22.30h, in der es ebenfalls um Computer Vision bzw. maschinelles Sehen geht. Die Autoren erwähnen dabei auch die Möglichkeit, dass die Community für korrekt annotierte Trainingsdaten sorgt, die dann den Machine Learning-Algorithmen zur Verfügung stehen – eine Sache, die mich auch beruflich beschäftigt. Bin gespannt, wie sich das alles weiterentwickelt.

Es ist immer spannend, wenn das, womit man sich (z.B. beruflich) einhergehend beschäftigt, beginnt, sich allmählich in der Gesellschaft niederzuschlagen, vor allem wenn die Entwicklung zuvor von der Öffentlichkeit unbeobachtet in „Elfenbeintürmen“ (Labors, Forschungs- & Entwicklungsabteilungen, Uni-Instituten udgl.) stattgefunden hat. Es ist nämlich damit zu rechnen, dass Anwendersoftware bald in der Lage ist, Bild- und Videoinhalte tatsächlich auch zu sehen. So wäre etwa zu erwarten, dass in jüngerer Zukunft nach dem Hochladen eines Bildes in einem einschlägigen Webportal vorgeschlagen wird, das Bild z.B. mit den Schlagworten „Auto“, „rot“, „Straße“ oder „Strand“, „Meer“, „Küste“ zu versehen, sofern eine einschlägige Szene abgebildet ist.

Was bereits Realität ist, sind lernfähige Gesichtserkennungsfunktionen in aktuellen Digitalkameras und Bildverwaltungsanwendungen. Mit den technischen Hintergründen dieser nun Alltag gewordenen Funktion beschäftigte sich die gestrige Ö1-Sendung „Digital.Leben“.

Maschinelles Sehen

[...] Wir Menschen können Gesichter ganz gut anhand von winzigen Details unterscheiden, wie aber macht das ein Computer? Die Antwort weiß Horst Bischof, Professor für maschinelles Sehen an der Technischen Universität Graz.

Ich erlaube mir, hier eine Kopie des Podcasts zur Verfügung zu stellen:

OE1_digitalleben_090205.MP3

Mehr zum Thema wird für die Ö1-Sendung „Matrix“ am Sonntag, 8. Februar, 22:30h angekündigt.