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 :)

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...