What the math courses don't teach us.....

Phew! This has been a long break in my blogging career. More like a sabbatical. Well, between the last blog time and now there have been many updates in my personal and professional life. Rather than getting bored with them I will be talking about some of the technical aspects of whatever I learnt - What the math courses that we do in our college don't teach us?
I have gone through many wierd courses which were always a pain and considered useless. Topology, algebra, finite element methods to name some. No you don't need to go in for wiki to know what these courses are about. It turns out that these courses form the basis of computer science. Alas, the profs could have told us this and we could have been more interested.
First of all, knowing about eigen vectors and the concepts of principal component analysis seemed to be too mathematical to help us in later lives. In reality, computer vision forms most of its theories around these concepts. I read plenty of papers about face comparison techniques available and the most basic one that came out in 1991 used principal component analysis. In layman language, PCA is used if we want to reduce the dependency to lesser parameters(components). This uses the eigen vector approach to work.
People who already knew this please don't hit me:D Others who are looking for more explanation could send me comments about the same:)

plug it in!

If you havn't seen Blade Pro yet, a Photoshop/PSP plugin by Flaming Pear Software, then you havn't lived! - Wow, a catchy line (can be found here)!
Interesting to see the cool effects it has.

Get what I say?

I found this idea very interesting when I was discussing with a colleague in office. Search for words in a video/audio. A difficult thing to do....a challenge! Made my eyes glitter. I was more than sure that this wont be there in the world yet.
BUT....
With the downpour of research in videos and images (segmenting objects , making sense out of a picture or a movie), this only seemed to be a natural extension. Maybe I came to think about all this late...moving behind technology,huh?
Anyways, so we googled for it and as we all know google digs down enough (like finding the heart of the ocean from titanic), we got this as out first hit(the Internet’s first spoken-word search engine for Podcasts). Interesting...!
Ask them - How does the technology work?
They'd say - Well, we could tell you, but then we’d have to… Um, magic.
Its an year now since this is available, after this silence I am sure they would come up with something even more mind blowing.
The podscope firefox plugin is available here . Podcast411 was the first to incorporate it in their site.

Can XPS contend with PDF?

XPS is an xml-based format by microsoft for competing with Adobe's PDF. There was a big hype about this before it was about to come out. Having a save-as XPS format in Office 12 and the talk about the competition that it will give to PDF was the in-thing few months ago(as was every vista related stuff). Now this so called hype has taken its space way below the PDF seat. Apart from few blogs that were written in October- November the last year, now much information is available on first few pages of google. I couldn't even get a nice XPS viewer easily.
The white paper on XPS is available here. Only time will tell whether it will be able to contend with PDF or not.

Peekaboo in PDF - Optional Contents

This might be a geeky thing to write, but i find PDF so damm interesting that i can't help but write about some of the features that I really love. Also, this might just be a small technical tutorial on one such topic in PDF which would help me (most of all ) in the future. Thats about Optional Contents in PDF.
Optional content is an appropriatly used term to signify a content in PDF that can be optionally viewed/printed/exported. You might call them layers in few cases. This gives the power to the PDF to hide its content depending upon various factors (called usage). Optional content is very clearly mentioned in the PDF reference manual. There are something called Optional content groups (OCGs),which controls the visibility of a graphics object. This is a dictionary (as every other thing in PDF) which contains a usage dictionary which specifies the nature of the content controlled by the group. For Example, Print = OFF meaning the content in the group can not be printed or, User = xxx,yyy meaning that xxx and yyy can view the document. Next is to determine the state of the optional content groups. There is an OCProperties dictionary which contains the list of OCGs it is refering to and the default states. This contains an AS array which has an event depending upon which the state of an OCG changes.
This might not be that interesting. The more interesting is the impact it has.
This is a good place to start. This example shows how PDF has the power to change its content depending on the zoom value.

flip my page

Page-flip showed me an interesting way of giving out cool effects using flash. How the book pages softly turn to show the next page gives a new experience.
I was wondering if this kind of flipping effects are available in animation too. Entering a new generation of rich-internal application is so exciting. Flash rules!

Rosetta !!

"Rosetta Stone" a term coming down from the egyption history has been used very conveniently for a tool for foreign language learning. You could check it out here.
"Rosetta" term has been used in so many different scenes ranging from company names to calender conversion application to spaceprobes. Its facinating to see the level of contrast and the spread of this term. One usage which is of much interest to me and to the many fellow Macintosh users is the powerPC emulator that will be shipped with intel-based Mac OS X(here).
The fasinating thing is that more often the usage of the term is in conversion or understanding something which is not in the domain.

Great going rosetta!!