Richard Stallman has a gun!

August 1999 and it was the first LinuxWorld conference at the McEnery Convention Center in San Jose California. Linus Torvalds had just finished one of his infamous Q&A keynote speeches. The room was packed to capacity with about 6000 people. Both Charlie Greco the president of IDG and Linus Torvalds were on stage and about to announce the winner of the $25,000 IDG/Linus Torvalds Community Award when all of a sudden something terrifying happened.

A poorly dressed, bearded, wild eyed madman runs onto the stage screaming and waving a gun. This crazed lunatic then approaches the podium, points his gun at Charlie Greco, says this is a "stick up" and demands some money. The audience was in shock and about to panic. Linus then calms everybody down and introduces the founder of the Free Software Foundation (FSF), Richard Stallman.

It was all a joke but unfortunately nobody was laughing. Well, Mr. Greco looked mortified and Richard Stallman was never again invited to speak at a LinuxWorld conference.

LinuxWorld is now OpenSource World

IDG is changing the name and the focus of LinuxWorld to OpenSource World. The penguin has been replaced. IDG is claiming that the "new event will focus exclusively on open source software and all things Linux." Whether this widens or narrows the scope of the conference depends on how you read that quote.

OpenSource World will be "co-located" with IDG's Next Generation Data Center (NGDC) event. This piggybacking will improve attendance but I take it as a sign that LinuxWorld is no longer capable of being a successful standalone event. This is disappointing news. I remember the first two LinuxWorld conferences in San Jose before the tech bubble burst and before the event out grew the space and was moved to San Francisco. Those were boom times. Anything seemed possible then.

LinuxWorld has been in a state of slow decline for the past several years. Red Hat stopped attending about four years ago and since then many of the large vendors have also left. What has me worried is that Linux is a neutral term while open source is more politically charged. Will this scare away vendors? Will the exodus trend accelerate? Will there even be an OpenSource World in 2010?

OpenSource World is scheduled for August 10-13, 2009 at Moscone Center in San Francisco.

5 for 5 after 5

Many years ago when I was in college I had a part time job as a computer technician working in downtown San Francisco. One evening I was scheduled to install a network for a company in the financial district. This job was to be done after normal business hours so that I wouldn't interrupt their daily operations. It was going to be a long night and I was hungry. It seemed like a perfect opportunity to take advantage of Arby's 5 for 5 after 5 deal. Five Arby's roast beef sandwiches for $5 after 5 PM.

So fast-pass in hand, I hopped on the Muni to the nearest Arby's at the Civic Center station to purchase my 5 for 5 after 5 dinner special, and then I hopped back on the Muni to return to the financial district. I had my cache of Arby's sandwiches and I was feeling good. I don't know what it is about Arby's but it always brings back happy childhood memories.

After exiting the Muni at the Montgomery Street station a dirty-filthy-scruffy homeless guy sitting by the side of a building asked me for some money. On general principle I never gave money to homeless people because I didn't think it helped them since they'd just spend the money on cigarettes, booze, or drugs. Today was different, so I asked "Are you hungry?" Richard the homeless guy said yes and I handed him two Arby's roast beef sandwiches with a couple packets of Arby's sauce. Richard opened the wrapper of one of the sandwiches, sniffed it, and asked if they were fresh. I told him that I had just purchased them and explained the whole Arby's 5 for 5 after 5 thing which was more than he really wanted to know. Richard the homeless guy then asked "do you have any fries?" Huh, fries? I was shocked and completely fry-less so I responded "sorry but I don't have any fries." That made Richard unhappy, he scowled at me, grumbled incoherently, and then I left.

Image Decimation Aliasing Distortion

Resizing an image to make it smaller is known as decimation. Below is an example image reduced in size by 50% (decimated by 2) that used a crude throw away every other row and column method. Notice the aliasing distortion:


The image distortion seen above can be avoided by filtering before the decimation process. The ImageMagick toolkit has a number of image processing features which can be useful here. The following ImageMagick command line performs the proper decimation and filtering:

convert a.png -resize 50% b.png

Below is the same image but this time the resizing is clean and distortion free:


The ImageMagick toolkit can also resize an image to any arbitrary size with a command line like:

convert a.png -resize 300x250 b.png

Image decimation aliasing distortion is analogous to reducing the sample rate of a time series signal without first low pass filtering. This DSP phenomena can demonstrated with the baudline signal analyzer's decimation feature. Go into the Input Devices window and select a Decimate By ratio. Recording a tone sweep is a good signal source for visualizing this phenomena. Next disable baudline's anti-alias filter and record the test signal again, this time aliasing distortion will be visible. This sort of aliasing is also know as frequency folding and some examples can be seen in the Full Duplex DAQ comparision sound card solution report.