Here I will write, what I need to be sure that I can find again, and far more which I probarbly don't need to find again :)

Saturday, December 1, 2007

Crossing modals, brain adaption test

A few days ago, I got an idea that it would be funny to cross modals. That is, convert visual information to audio, and vice versa, the idea for vision to audio is simple and I started working on some of the required sub-systems. Until a friend of mine, after informing him of the idea, informed me that such a system is already devoped.

The most interisting part is itthat the transormation function is working exactly as I would have done it myself, and it is reported to make it possible to make blind people see! coool.

Vision->audio explenation.

The scientific consideration is possible to find at ( sample rate, human sensory bandwidth problems etc.).

But a simple overview is given on the figures at: (source), I am apparetly not allowed to show the image here, so you have to navigate to the adress to see the image.
To make the sound experince more smooth, I am considering if adding a gausion over the entire image would help, the referenced system is not trying to smoothin the audio representation from one image to another, but considering the very slow framerate the system seems targeted at ( around 0.5-1 sec for each image playback) , it might be a bad idea to throw away information, there seems to be a problem regaring the bandwidth of the ears, the framerates I would aim for would probably only give a headache.
anway, if you are interested, both the source, and a working windows application can be downloaded from

Future City

We are going to have dynamic houses, not dynamic in the way you are used to think dynamic houses.

To understand the concept, think that you do not own a house, instead, you own a location, and a configuration amount. The configuration amount + your imagination is the only limit, when you want a house, you comuninicate to your configuration, that it must manifest a given house. If you have more need of a garden, a swimming pool and/or something else, you communicate the wish to your configuration and it obeys.

The idea is now introduced, you might be thinking; crazy idea, how is this possible. it is simple. you own millions of nano robots, which can attach to each other to form inanimate objets at least.
I estimate this is possible in 10-50 years from now.

But I am not sure how we can preserve nature in such a city. ofcourse there could simply be spots of nature enviroment, and small capsules and perhaps a tunneling system where the configarable robots lives, in this way the configuration can manifest where it is needed... and live in harmony with nature.

Friday, October 19, 2007

3d laser scanner

Ok not much happening the past few dayes, it seems...

In reality, it is because I am bussy working on a 3D laser scanner with a friend of mine from the school, We have created a blog, right here on blogspot, which we hope to use as a journal for what we have done.

Sunday, October 7, 2007

Fast median image


While reading a paper about 3D object reconstruction, the authors mention that median images would be good to surpress camera noise... They state that thre downside of mediam images are that they are slow to calculate.

I would say... not soo. The update pr. pixel can be made as a O(log(n) ) problem.
if we treat every pixel value as a sorted lost, insertion can ( as far as i remember, be given the complextiy as stated), the rest is straight forward. The reading of a pixel value will be a table lookup -> resulting in a O(1) complexity.

The following defines the interface as I think it shall be.

class MedianImage {
  • MedianImage( width, height, filterdepth )
  • void Accumulate( x, y, value )
  • datatype Get(x,y)
  • datatype AccumulateAndGet( x, y, value )

Another possible interesting thing to look at would be the pixelwise variation, a very crude measure of camera noise could be made like this, furthermore, it would be possible to use this information as a simple activity localization.

class StatisticalMedianImage : MedianImage {
  • datatype GetVariance( x, y )

One yet undefined thing is what data we choose to throw away when adding pixel values to a full buffered pixel, I propose throwing away the pixel whit the longest distance to the median of that pixel.

I will implement this as soon as possible. now I will sleep.

Saturday, October 6, 2007

Shit vista!

Ok around 3 dayes of vista, and I had to reinstall. The machine simply booted into black screen! Not even the repair console worked...

The good thing is that I have installed xp on a partition also now.. sob really looking forward to installing linux...

Wednesday, October 3, 2007

New laptop - It is nice ;)

Finaly I did it. I bought a new laptop, I have been thinking about it for very long time, and even sleept in front of a store for nothing.

Actually, I was thinking "I don't need a new laptop", until my old trusted IBM P-IV 1.4 GHz laptop began to have big problems accesing disks attached to the secondary controller. I even tried to revoke my zombi celeron 500MHz Toshiba laptop with a mixed succes... Now it is reminding the audience of an old movie.. The computer shows randomly white stribes on the screen, and sometimes, begin fading to.. white... from outside to the center of the monitor, whery odd, and the machine is frozen while it is experiencing these magical moments...

O.K. enough babling
The new excellent machine is a Fujitsu siemens 2GHz turion64x2 with loads of hd(320GB), 2GB of memory AND: gf8600GT graphics :D. The last was the primary requirement for buying a new pc, since I will now be able to code the GPU in C.

mmmm power.

Machine, full name FUJITSU SIEMENS Xa AMILO 2528, is generally perfoming excelent. the bad part is, that I have not been able to install any linux distributions yet, I think they fail to find the dvd-drive, and thus cannot read the media :(.

Machine ships with Windows vista, which I had sworn I would never get to use, but once again I am beaten by microsoft and the masses, and what can a poor man do... But it runs better that I expected, everything is ALMOST as snappy as with KDE on my P-IV2,4GHz ;).

Now, what have caught me with so amazing surprize, is the bizarre amount of windows vista updates I am downloading and installing. I have activated the baground installation and download of updated, and now, 3 dayes after I bought machine, I still have to wait around 1-2 hours every day on windows shutting down, and windows starting... configuring updates, 1-2 hours every day. way to go microsoft. you have made the fastest machine i have ever had the on average slowst starting device I have ever owned. I will not even coment on the other bizare things vista throws on me. I will instead try to get the most out of the operating system.

And in 3-4 month, I will hand in my assignment, kill vista, liberate the free people and install linux...

luckily there is lot of fun stuff I can use it for, I have installed visual c++ 2008 beta , SDL-development, platform SDK and openGL, next thing I will download is Nvidia's CUDA, and then the fun begins :)

ohh and another fun thin, which I have to share with the world...
Note: "Fuldført" means completed, "Mislykkedes" means failed... If in doubt, this is the log of windows update...

The really funny part is the attemts to update to .NEt 3.0 since visual c++ ships whit .NET3.5...

Sunday, September 30, 2007

Compiling codeblock from svn on ubuntu 7.04

I had some trouble getting this to compile, the bootstrap failed with some WX_[something], and the solution was simply to pull the package 'wx-common', at this point I had already installed wx-2.8.? development.

the solution was found here

UPDATE: the wxwidgets which are in the stock ubuntu repositories are buggy, follow the instruction here, if wxwidgets hangs.

Monday, September 24, 2007

VIA Epia EX1000 an installation adventure

For some time, I was playing with the idea of building a noiseless computer, even though I spent a lot of money on silencing my ~6 year old P4, it never become as silent as i hoped.

Ofcourse I think that being power effecint is excelent so discovering the VIA-epia ex1000, and reading their adds promising that I would both safe the planet, get super effecint computing and doing this fanless, I decided to buy one.

It is important to note that I do, and did not, plan for using this computer for playing games. Mostly I will do write some code, browse the net and sometimes watch a movie and all the time listen to music. This means that the computer doesn't need 8processors, 6GB of rams and ~1TB harddrive ;)-

Here is the wonderfull machine right after unpacking it.

It is clear from the photo that it is actually a very small computer (mini-itx form factor)

The key specs are:
  • VIA C7 1GHz processor
  • S3-unichrome pro II IGP graphics card
  • Fanless
  • 17.5 x 17.5 cm footprint
After about 1-hour, I had taken a cd-rom drive from my old computer, a sata-harddrive whit a unused partition and welded a switch for that easy on/off function a computer really needs :).

Sabayon: nogo
My initial try was sabayon which as expected didn't work, sabayon is targeted high-end computers, so I would have been surprised if it worked... to be fair, the sabayon live-cd did a fall-back to a text installer, so I would still be able to do an installation, but sabayon without the graphics is... just wrong :)

Ubuntu + official VIA drivers
Ubuntu on the other hand booted just fine, installing everything goes whitout any problems, and network is working without any problems. The graphics card and sound is a totaly different story, I haven't really worked on trying to get the sound to work yet, but managed after a few days to get the officiel VIA drivers to work, I have never seen so horrible installation instructions... opengl acceleration is with the offcial drivers working fine. but playing movies with mplayer and totem works rather badly, the cpu-usage was arround 60-70% for fullscreen lowres video, and it is supposed to be hardware accelerated according to via's website.

While searching I found the openchrome drivers, so I decided that I would like to try the perfomance of these, since the openchrome drivers are distributed as source, I installed gentoo, then I am sure that the source I have avaliable is the source used to compile the running system.

Gentoo + openchrome drivers
So I installed gentoo, having some problems getting the drivers to work, ( network also works out off the box ). After a day or two + some help from the openchrome user-list, I finaly get X accelerated, that is, there is 2D acceleration, no 3D, and playing video is still as cpu intensive as finding the complete chess game tree...

I still never got sound to work in linux (yet), bt at this point in time, I decided that I really wanted too how the machine really performs, whit fully functionell drivers etc.

Windows XP
sob, I decided to install XP

Installation goes without any problems, out of the box, network works (y), no surprise, I insert the VIA-driver cd, and installs everything.

The EX1000 now features sound, 2D and 3D graphics accelerationd and working composite tv-out for my pal-tv , the s-video out produces black and white pictures, no mater what I select of color type.

Everything seems fine, until I loads a video from you-tube, the machine play's the video at an amazing 3-4fps in fullscreen (1280x1024) and a little faster at (1024x768) still far from usable.

Sample game perfomance - system meltdown.
To do a quick test of 3D, I installed Dungeon Siege II, which I was able to play without problems with my ti-42000. Not so smooth on this machine, with some good will, it could be considered playable, but for some reason the machine crashed from the transiotion from level one to level two, reseting the machine resulted in black screen! All semed very bad, I did shutdown the machine and went to bed, next day the machine wouldn't boot, complaining some file was corrupt, ofcourse, I don't know if this is a faulty disk, or a hot motherboard which issues crazy commands to the disk... I can only speculate, reinstall, and retry. which will be done.

For now, the machine have overall disappointed me. Thats why I was pleasently surprised by the clear sound comming from the sound card, VIA DO call it HD audio, and altough I don't give much for these kinde of noncense buzz words (I believe in signal to noise ratio ;) ) , I have never heard so noiseless sound from a computer before, This makes me considerable more happy.

Video playback
With the drivers installed and everything, I suspected that the machine would be able to play any kind of movie, playing DVD's is no problem, everything goes smoothly, the processor is working at arround 60-70%. Since the machine has hdtv output (it says so in the bios), I decided that I would try to download some hdtv sample movies, her the perfomance is.... strange I think the correct word is, it seems like everything is playing ok, at least it can play a wmv-720p sample movie, almost whitout problems, and ofcourse there is more delay with a wmv-1080p movie. The strange thin is, that the sound and image is not syncronized... This might be a driver problem...

I have build a machine, which was supposed to replace my old machine, but to be honest, I am very dissapointed, the machine is simply to slow. Perhaps I was to naive, to think that a 1GHz ulv machine could satisfy my desires. I am currently considering wheter I will use this machine instead of my VHS and dvd, const are mostly slow bootup time, pros are sofa surfing :)

Thursday, September 20, 2007

Energy waste

I have just bought a energy measurement thingy (picture) to measure how much energy different stuff at my home uses... and the first thing I would like to measure was how much my new via epiaEX1000 used.

Happily inserting the device between the socket and my epia, I almost recieved a hard-attack. My old power supply (soon to be replaced) uses a whooping 18W when the computer is turned off !!!!!!!!!

What the hell is this shit, it cannot be true, ok I looked in the manual for the measurement device, and it states that there is one can expect an error on 10-15%, espicially below 60W, still, assuming it is 15% to much it is showing I still waste at least 15W every single minute.

Just thinking, should I now conclude that I have to use the machine all the time to reduce the energy waste ;)

Note: The crappy power supply is a Chieftec HPC-360-202.

//TODO - add a list showing power consumption from my computers given different workload, suggestion are welcome for what I should try

Wednesday, September 19, 2007

Solved ATI problems AX800pro ubuntu

Finally I got the graphics card working, I had it working with gentoo for a long time, and now also with ubuntu.

the final error message I zoomed in on after long time was.

From /var/log/Xorg.0.log
(EE) fglrx(0): [agp] unable to acquire AGP, error ""xf86_ENODEV""xf86_ENODEV""

from the kernel (dmesg):
[fglrx] Internal AGP is not supported in 2.6 kernel.

The sollution was found from here:

(even though I don't understand german :) )

This did the trick !
rm -fr /lib/modules/2.6.20-*-generic/kernel/drivers/edac

Ahh on to opengl programming.
Drawing a triangle...