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Topic: Ellipse Detection with matlab function
Replies: 25   Last Post: Sep 4, 2013 7:35 PM

 Messages: [ Previous | Next ]
 EoD Posts: 3 Registered: 6/15/07
Re: Ellipse Detection with matlab function
Posted: Jun 15, 2007 10:03 AM

On 15 Giu, 15:05, "Peter Bone" <peterb...@hotmail.com> wrote:
> EoD wrote:
>

> > Anyone knows how I can detect theellipsefrom one image, using
> >matlab
> > functions Hough,Houghpeaks,HoughLines?
> > Anyone have somekind ofmatlabalgorithm that makeEllipse
> > Detection?

>
> > Thank you all!
>
> Fullellipsedetection is rarely performed because it is very slow.
> It requires a 5 dimensional parameter space - as opposed to 2 for
> straight line detection and 3 for circle detection. Is there anything
> you know about the ellipses that can reduce the number of parameters
> used to represent them? For example, orientation, size, eccentricity,
> position. If you're looking for a particular shape and orientationellipseand you only want to find the position then you can adapt a
> circle detection algorithm, from the file exchange, to draw ellipses
> in the voting space instead of circles.
> I believe that the Hough transform functions that come withMatlab
> are for straight line detection only.
>
> Pete

Thank's a lot Pete,
well my project is to make face detection from images,
I can suppose that the face orientation is fixed, I suppose
that the axes which describe the vertical semimajor axe is longer than
horizontal axe.
I'm tryin to modify that implementation of Hough Transform

http://basic-eng.blogspot.com/2006/01/hough-transform-for-circle-detection_23.html

but i can't understand how modify it.
I understand that i fix for any iteration any radius value and
horizontal axe.

If you have some code example or pseudo-code algorithm and you can
send me it

Excuse for my english.

Thank you
EoD

Date Subject Author
6/15/07 EoD
6/15/07 Peter Bone
6/15/07 EoD
6/15/07 Dave Robinson
6/15/07 Peter Bone
6/19/07 EoD
8/20/07 Marcelo Flores
7/31/08 Allegra
2/3/09 Guest
2/15/09 sMiL E
3/23/09 kajal
4/7/09 Idillus
11/4/09 Ricardo Grana
11/6/09 Ali Gurbuz
12/23/09 Brian Millikan
2/2/10 Carlos
5/23/10 ?ukasz Nalewajko
2/15/09 Dave Rolkosky
11/24/09 Msizi Khoza
6/23/10 John
7/22/10 Will Stott
11/10/10 George
11/10/10 ImageAnalyst
1/11/12 Max
9/4/13 apmyst@gmail.com
10/17/12 Andri Pranata