Histograms

It has been some time since my last post. I was trapped by a number of technical issues that meant I was not even sure my SOM was working properly. Through the debugging process I created two variations of the current system. Both use temporal timing. That is the SOM is not triggered by the motion analysis, but runs at a fixed interval. This was done to simplify the patch as much as possible. The second variation used a histogram in place of the usual pix_dump method (of feeding the raw pixel data to the SOM).

I have learned two things. The first is that the likely cause of the  lack of organization in previous work was due to timing issues. That is the first thing I will go back to fix in other code branches. The second is that the idea of using a fixed camera may be problematic. In my experiments I was able to making a working system using the pix_histo object and passing the histogram to the SOM, rather than raw pixels. This works surprisingly well for a dynamic and moving context (that is it works best if the camera is moving, not a static camera). Of course when using the histogram the system is no longer using the raw pixel data, and therefore not making a pixel by pixel comparison. In orther words the pixel-by-pixel method is most appropriate for the static camera, where the histogram method may be more appropriate for the moving camera. It is clear that the histogram method does not work very well with a static camera.

Histogram method with static camera:

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Histogram method using a moving camera:

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