[Insight-users] Re: ellipse detection

[Radomir Skowron]

Dear Sir,

Thank you very much, the information is very helpful. I experimented with 
the Hough transform to find circles (not ellipses yet) and it works quite 
ok, but I have one problem - I must pass the number of circles I expect to 
find but in fact, I would like the program to find all circles that exist in 
the image. If I set the parameter Number of Circles to high, I get many more 
circles and most of them are improper. I hope there is a way to count the 
circles that appear in the image using the Hough transform but do you know a 
method to do this. Is your sugestion B (model registration) a solution to my 
problem? i.e what is the best way to count the number of circles in the 
image (and if I know this I will then tackle with ellipses). Thanks in 
advance.

Best regrads,
Radomir Skowron


----- Original Message ----- 
From: "Luis Ibanez" <luis.ibanez at kitware.com>
To: "Radomir Skowron" <radek at complex-media.pl>
Cc: <Insight-users at itk.org>
Sent: Sunday, March 13, 2005 7:27 PM
Subject: Re: ellipse detection


>
> Hi Radomir,
>
>
> You may want to consider the following two options
>
>
> A) Modify the classes for Circle Hough Transform
>    in order to extend them for Ellipses
>
>
> B) Use Model to Image registration, with an
>    EllipseSpatialObject as a model.
>
>
>
> Option (A) is better for the case where you
> expect any number of ellipses anywhere in the image
>
> Option (B) is better when you have some idea of
> where in the image you can expect the ellipses to
> be, and you have a rough estimation of their
> parameters.
>
> For both cases, you will find information on the
> ITK Software Guide
>
>
>     http://www.itk.org/ItkSoftwareGuide.pdf
>
>
>
>
>
>    Regards,
>
>
>
>        Luis
>
>
>
> ------------------------