Contribution: circles and hough transform

[Stéfan van der Walt]

Hi François

On Wed, Jan 9, 2013 at 11:01 PM, François <francois.boulogne at gmail.com> wrote:
> Is Skimage interested in this implementation? (I don't want to spend much
> more time to polish the code if there is no need)

Definitely!  I've also been thinking about a more general hough
transform that uses the Ax + By + Cxy + D definition of certain
curves, but never got around to it (there's an earlier mail about it
on the list).

> If the answer is positive, it can be done in two steps:
> * add a method to draw circles. The current "circle" method is for disks. We
> need circles (very easy to write). This is already done, but in pure python.
> I saw that drawing methods are implemented in cython. I have never used
> cython before, but it must be easy (I guess). I implemented two methods
> (Bresenham or midpoint circle and Andres), both are useful I think.
> * write the hough algorithm for circle. Done for a Quick and dirty usage,
> but it's not suitable yet for integration (not safe).

Both patches would be very welcome!  Let us know if you need any help
getting started.

Regards
Stéfan