Particle Filtering - Survival of the fittest

I recently studied dynamic system models such as Kalman and Particle Filters.
For Kalman Filter I followed a Matlab demo that can be found here.

In this demo, the simple problem of tracking a ball is addressed using a Kalman Filter. The input sequence is of a ball, which is travelling at varying velocity and which is occluded in some frames by a box. I think this is a great example to demonstrate the power of dynamic system  models, especially the occluded frames can be used to test how good a dynamic model is. Here is the actual sequence:

As you can see the ball goes underneath the box and comes out of the other end. If our dynamic model is accurate it will be able to predict the state of the ball even when it is not visible, and should match the position when the ball comes out.

The journey of my sketches

Okay, this post is not related to anything this blog is about, however I have a feeling that this might be interesting for atleast someone.

Well when I started to write this post, it was more about how I learned to sketch with all the sketches I did and the reasons why I did them. Now after writing this post, it looks more like a journey, a journey which started sometime back. I had no skill, no proper tools, no knowledge about sketching and at some point I never thought I would do it at all. This all started one day when I was extremely bored and free, and I thought it would be cool to learn how to sketch. I started looking at other people's sketches on deviantart and tried to replicate most of the things they had done in their sketches.

My first sketch had soldiers in them. At the time I used to watch TV series "Band of brothers" and thought it would be cool to do one of the wallpapers in pencil. It was hard at first, but gradually I learned a few tricks. This was pretty basic and required not a lot of skill.

click to enlarge