Skeleton analysis (proximity to Halloween coincidental:)

[Jarek Sacha]

I am looking for a plugin/macro (or a hint of an algorithm/reference) to analyze a skeletonized image. In particular to count number of brunches at nodes and length of lines between nodes.

Thanks,

Jarek

[Sami Badawi-2]

Hi Jarek,

The ShapeLogic plugin analyzes skeletonized images.  This is used in a
letter recognition example.  It will trace the lines, vectorize them
into polygons, find intersection points and categorize them as e.g. a
T junction or a hard corner.  For length measurements there is both a
raw point count and a poly line that can be turned into a length.  It
currently does not write this information out, even though there is a
print polygon method used in the unit tests.

You could either try to add this functionality yourself, make a
feature request to ShapeLogic or just take the code you need from
ShapeLogic, since it is under MIT license.

-Sami Badawi
http://www.shapelogic.org

On Tue, Oct 28, 2008 at 2:35 PM, Jarek Sacha <[hidden email]> wrote:
> I am looking for a plugin/macro (or a hint of an algorithm/reference) to analyze a skeletonized image. In particular to count number of brunches at nodes and length of lines between nodes.
>
> Thanks,
>
> Jarek
>

[Ignacio Arganda Carreras]

Hello Sami,

What would be the sequence of ShapeLogic menu commands to do what you
explained?

ShapeLogic only works with 2D images, right?

Thanks a lot!

ignacio

Sami Badawi wrote:

> Hi Jarek,
>
> The ShapeLogic plugin analyzes skeletonized images.  This is used in a
> letter recognition example.  It will trace the lines, vectorize them
> into polygons, find intersection points and categorize them as e.g. a
> T junction or a hard corner.  For length measurements there is both a
> raw point count and a poly line that can be turned into a length.  It
> currently does not write this information out, even though there is a
> print polygon method used in the unit tests.
>
> You could either try to add this functionality yourself, make a
> feature request to ShapeLogic or just take the code you need from
> ShapeLogic, since it is under MIT license.
>
> -Sami Badawi
> http://www.shapelogic.org
>
> On Tue, Oct 28, 2008 at 2:35 PM, Jarek Sacha <[hidden email]> wrote:
>  
>> I am looking for a plugin/macro (or a hint of an algorithm/reference) to analyze a skeletonized image. In particular to count number of brunches at nodes and length of lines between nodes.
>>
>> Thanks,
>>
>> Jarek
>>
>>    
>
>
>
>  

--
Ignacio Arganda-Carreras
Escuela Politécnica Superior
Laboratorio B-408     Phone: [phone]
Universidad Autónoma de Madrid
Ctra. de Colmenar Viejo, Km. 15
Madrid 28049,  Spain

E-mail: [hidden email]
Website: http://www.ii.uam.es/~iarganda

[Sami Badawi-2]

Hi Ignacio,

The command to run the letter recognizer example is:
Plugins>>ShapeLogic>>CapitalLettersMatch

It is described here: http://www.shapelogic.org/getting-started.html

CapitalLettersMatch is a macro.  The sequence of steps is:
* Turn image into binary
* Skeletonize
* Trace lines into polygons
* Analyze geometric features of polygons
* Match geometric features for each polygon against rules for letters
* Print a list of letters that has been matched to polygons

The 2 first steps are ImageJ commands, all the steps after is done by
a ShapeLogic plugin called: StreamVectorizer.java.

In ShapeLogic 1.4 I will add a command that writes out a simple report
of all the geometric features for all the polygons.  This should be a
minor change.  Let me know if you have any requests for what report
format would be useful, or if you have questions about how to modify
ShapeLogic yourself.

Yes ShapeLogic only works on 2D images.

-Sami Badawi
http://www.shapelogic.org

On Wed, Oct 29, 2008 at 6:40 AM, Ignacio Arganda Carreras
<[hidden email]> wrote:

> Hello Sami,
>
> What would be the sequence of ShapeLogic menu commands to do what you
> explained?
>
> ShapeLogic only works with 2D images, right?
>
> Thanks a lot!
>
> ignacio
>