image recogniton?

[Almar Klein]

2009/1/7 Li Han <lihang9999 at gmail.com>

> On 1月7日, 上午4时14分, J Kenneth King <ja... at agentultra.com> wrote:
> > I'm curious as to what application the solution to this problem is
> > practical for all of its difficulty?
> Sorry, I oversimplified the question because of my poor english. It is
> an analog compass whose value we need to read  into the computer every
> second. We use a video camera keep shooting it, and the compass and
> camera are  fixed.
> --
> Li Han
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>

The compass of the needle looks like a line. Lines can be best detected
using second order (Gaussian) derivatives.
scipy.ndimage.gaussian_filter provides a filter you can use for that.

Then maybe PCA to find the direction of the needle, and you're done!
There's probably more to it (there always is), but this might get you
started.

  Almar
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