Mirror Image

Mostly AR and Stuff

Learning mathematics is good for the soul

At The n-Category Café David Corfield is talking about mathematical emotions. This is about ‘emotions belonging to mathematical thinking’, specific feeling related to mathematical intuition, meaning and sense of the rightness. In the end he is referencing to spiritual motivation of mathematics. From myself I add that those thoughts are closely related to the last book of Neal StephensonAnathem

19, November, 2009 Posted by | Uncategorized | , , , | Comments Off on Learning mathematics is good for the soul

Fake Style at Cosmic Variance

From comments to Fake Stile

Ahmed say:
….
– It is not always clear what emotions the author is trying to communicate, and that sucks. Smileys/emoticons can help here. For e.g., “This is problematic :) ” can mean the problem is finally resolving some bigger issue. “This confirms X :( ” means a problem is persisting. The smileys will serve as guiding points in the storyline of a paper, so we don’t have to read all of it.

Moving from style to more general regulations:

– Every paper not within the technical grasp of a good undergrad in physics/math/similar should be accompanied with a sister-paper explaining it to (at minimum) such an audience. Just to make sure the author (and the committee!) actually knows what’s going on. String theorists can of course just write an apology or something.

4, November, 2009 Posted by | Uncategorized | | Comments Off on Fake Style at Cosmic Variance

Fast Fourier Transform for P2P networking

Very unusual application of FFT in this arxiv paper. Butterfly diagrams for radix-n FFT allow building P2P network with maximum diversity, reliability and flexibility and minimum complexity.

19, October, 2009 Posted by | Uncategorized | , | Comments Off on Fast Fourier Transform for P2P networking

Problems

During the tests I’ve found out that bundle adjustment is failing on some “bad frames”. There two ways to deal with it – reject bad frames or try to understand what happen – who set up us a bomb? :-).Any problem is also an opportunity to understand subject better. For now I suspect Gauss-Newton is failing due to too big residue. Just adding Hessian to J^{T}J does not help – I’m getting negative eigenvalue. So now I’m trying quasi-Newton from the excellent book by Nocedal&Wright. If it will not help I’ll try hybrid Fletcher method.

PS It looks like the problem was not the large residue

6, October, 2009 Posted by | Coding AR, Uncategorized | , , , , , | Comments Off on Problems

New polymath project announced – deterministic way to find primes

New polymath project – massively collaborative mathematic project announced at the polymath blogdeterministic way to find primes – given an integer k, is guaranteed to find a prime of at least k digits in length of time polynomial in k.

29, July, 2009 Posted by | Uncategorized | , , | Comments Off on New polymath project announced – deterministic way to find primes

Zen of debugging

Shenxiu produce gatha:

The project is a source tree,
the code a standing mirror bright.
At all times polish it diligently,
and let no bugs crawl.

When a fra passed the rice mill chanting Shenxiu’s gatha, Huineng immediately knew this verse lacked true insight. He went to the wall, and asked a avout there to write a gatha of his own for him. The avout was surprised, “How extraordinary! You can not write assembly code, and you want to compose a gatha?” Whereupon Huineng said, “If you seek supreme enlightenment, do not slight anyone. Lowly java programmers may have great insights, and assembly coders may commit foolish acts.” In veneration, the avout wrote Huineng’s gatha on the wall for him, next to Shenxiu’s, which stated:

Project has no tree,
nor is the the code a standing mirror bright.
Since all is originally empty,
where does the bugs appear?

Huineng then went back to rice pounding. However, this gatha created a bigger stir; everyone was saying, “Amazing! You can’t judge a person by his looks! Maybe he will become a Living Saunt soon!” However, when the alarmed Hongren came out, he just casually said, “This hasn’t seen the essential nature either,” and proceeded to wipe the gatha off with his shoe.

Huineng refactoring code
Huineng refactoring code

6, July, 2009 Posted by | Uncategorized | , | Comments Off on Zen of debugging

Sand Animation

Just discovered for myself another new media – sand animation
Here is a great example – Russian artist performance about memories of WWII

16, June, 2009 Posted by | Uncategorized | , , | 1 Comment

Bing vs Google for augmented reality and computer vision

I’m using Google a lot for my work, looking for articles, unknown to me definitions and techniques and so on. So I’ve decided to check Microsoft Bing too.
First test – augmented reality
Google – definition in the first line, links give pretty comprehensive coverage for beginner
Bing – four obscure links with job and phd references

Second test – MSER definition
Google – give definition in the first line
Bing – unrelated garbage

Third test – preserving symmetry in cholesky decomposition
Google result
Bing result
Similar results. Both engines relay on the wikipedia heavily

Forth test: “multiscale segmentation”
Google result
Bing result
Surprisingly I like Bing results better.

Conclusion:
Google engine seems have more “common sense” and more useful for introduction into subject. Could be because of bigger indexed base.
Bing could be actually useful in specific searches.

15, June, 2009 Posted by | Uncategorized | , , , | 4 Comments

Open Source programmable camera for image processing

Interesting product – camera for computer vision applications, with open sourced DSP
camera
From sci.image.processing:
“The entire camera (hardware as well as software) is open source. It features a 752×480 pixel CMOS sensor, 64MB of SDRAM and 4MB of flash, Ethernet and div. IOs.
The camera runs a uClinux and comes with an image processing framework.”
Datasheet is here

14, June, 2009 Posted by | Uncategorized | , , | Comments Off on Open Source programmable camera for image processing

10,000 Year Clock construction is moving forward

Via slashdot
model
model
And if you are reading this blog and havn’t read Anathem yet, you should give it try :)

16, April, 2009 Posted by | Uncategorized | , , , , , | Comments Off on 10,000 Year Clock construction is moving forward