Wednesday, April 18, 2007

Pandora

Its been ages that I had a post, and it was most probable that I would not have posted anything on this as I am working on my own web space now, keep your eyes on www.confusionart.com
but I was just impressed by this.

Many of you know that I work in the area of image retrieval, the basic idea being - "I should be easily able to retrieve the image that I want to from my database, and find images that I have a picture of in my mind, but one that I have never seen before." One of the paradigms of image retrieval is call query-by-example where in you provide a query image and the system should return all the images it feels that are *similar* to the query image and this operation is said to be successful if the user also feels so.

Now last winter I was talking to Doug ( another researcher at UCSD, working on a similar problem but in the domain of music annotation and retrieval) that I need a simple software that, given a song should be able to retrieve all the songs that are *similar* to the query song. He being a specialist in music analysis said that similar is not a well defined term as similar could mean by the same band, same year, same genre, same beat, same instruments and lot many things. Moreover a song changes over time and its not trivial to define similarity. From a non-expert point of view I still felt that it should be possible to define *similarity* the way I was thinking - It does not matter who is the singer, what year it was composed, what genre it is, just plain similar in perception. Alas I went home in winters and things went dud!

Recently came across www.pandora.com and they have achieved what I wanted, to an extent. Although everything on their database is manually annotated and hence in a way they have provided manual similarity measure between songs. You give them a song or artist and it keeps on playing songs *similar* to your choice. They do so by matching around 400 features of the song/artist (after all Doug was right, there are indeed many parameters to define similarity on) which have been provided by professionals to each song. But the result is just awesome. I tried to find songs similar to *Enya* and I must say it has been two days that I am on the same channel and it has played just awesome songs from various artists. I wrote this blog when it played *Dream of dolphin* by Enigma, one of my favorite. Bang on one great *similar* songs.

So after www.dhingaana.com this has become my favorite site for music. :)