Friday 27 March 2015

Kalman away

Well took long enough but I have a Kalman filter working. Thanks to help and code from my dissertation supervisor Hannah Dee. I have managed to tweak her code that uses Kalman2d which can be found here to fit in with my scenario. Example of what it is currently doing can be seen below.

Here shows the Kalman filter in action(the green line) however at this point it jumps between the two people in the box currently


I have added some basic checking for the HoG(Histogram of orientated gradients) and Kalman filter so that if a HoG is not detected the bounding box is drawn in the last place it was located. If it then re appears the Kalman filter then is updated with the new location. This is done by searching with a buffer with in the range of last HoG detection, this is assuming the person has not travelled far and there is no one else nearer.

The issues I am having with two people coming near to each other that the tracker swaps over is not an issue. The reason being as if two people come close to each other and one gets the tracker from the other then the other one will get their tracker. One way I can mitigate this is to start the search in the direction the person was travelling so that way the person is more likely to get their tracker back.

I am currently only tracking one person but now I have a goal I feel I can really push this through. My goal is to build a person object that will keep track of locations to help mitigate occlusions and count them. This will be using HoG detector as the initialiser, mean shift, Kalman filter and cam shift to help determine location helping keep a more accurate track of people. Background subtraction will be used as evidence to show that something is moving here chances are someone or something is here.

I am hoping to be able to determine in scene exits by determining if a number of person detectors go dead at the same location. If they are predicted to go off scene then that is a normal exit but can monitor exits to focus detectors more.



Any way this will be my last blog post for a while as I am off to sunny Lloret de Mar for my first vacation abroad with dance sport. Should be a good time sportsvest who are organising it have made it look like it is going to be an epic time. So speak in a week and a bit.

Lloret de Mar




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