[Insight-users] Connected component statistics

[Miller, James V (Research)]

Gaeton, 

Center of gravity and bounding box could be added to the RelabelStatisticsImageFilter
since they are simple calculations.  However, it is a bit of a side-effect.  The 
volume is calculated in the RelabelStatisticsImageFilter because it is used by the
filter to order the labels.  Since it was already calculated, it made sense to allow
the user to access it.

The best place for these measures and the more complicated measures would be a class 
similar to the LabelStatisticsImageFilter. The filter should be called something like
LabelMomentsImageFilter (and calculate ImageMoments as well as geometric moments. Or maybe
something like LabelShapeImageFilter.

I do not see any reason to use the ImageSpatialMaskObject for this task.  Usually, you 
would want to calculate these features for EVERY component.  So it best to run through a 
filter that does it.

Jim

-----Original Message-----
From: Gaetan Lehmann [mailto:gaetan.lehmann at jouy.inra.fr]
Sent: Monday, July 18, 2005 4:57 AM
To: Miller, James V (Research); Karthik Krishnan; Richard.Beare at ieee.org
Cc: insight-users at itk.org
Subject: Re: [Insight-users] Connected component statistics



Hi,

I'm also interested in basic measures such as volume, center of gravity  
and bounding box.
I think to work on it this week, so it should be great to define where to  
implement methods to get those informations.

RelabelComponentImageFilter is already able to give volume, so it should  
be a good place to add other very simple informations like center of  
gravity and bounding box.
It don't seem to be the good place for more complex info such as  
perimeter/surface... perhap's ImageMaskSpatialObject is a better place ?

WDYT ?

Gaetan

On Fri, 15 Jul 2005 20:39:46 +0200, Miller, James V (Research)  
<millerjv at crd.ge.com> wrote:

> The LabelStatisticsImageFilter will calculate statistics for each  
> component.
> Currently, the LabelStatisticsImageFilter calculate mean, variance, sum,  
> count,
> and histograms.
>
> We plan to add another filter that calculated the moments (either image  
> moments or
> geometric moments) of each component. I have been waiting for it to be  
> completed and
> may have to just write it myself.
>
> Also, the RelabelComponentImageFilter allows you to query the volume of  
> a component.
>
> Jim
>
> -----Original Message-----
> From: insight-users-bounces+millerjv=crd.ge.com at itk.org
> [mailto:insight-users-bounces+millerjv=crd.ge.com at itk.org]On Behalf Of
> Karthik Krishnan
> Sent: Friday, July 15, 2005 10:10 AM
> To: Richard.Beare at ieee.org
> Cc: insight-users at itk.org
> Subject: Re: [Insight-users] Connected component statistics
>
>
>
>
> Richard Beare wrote:
>
>> Hi,
>>
>> I've found ConnectedComponentImageFilter and
>> RelabelConnectedImageFilter, but I haven't been able to find anything
>> that returns measures of the connected components -- e.g. area/volume,
>> perimeter/surface area, centre of gravity, ellipse moments and minimum
>> enclosing rectangles.
>>
>>
> You could threshold the labelled image to get each connected component
> and...
>
> If you are using CVS ITK, I had put a method recently :
> ImageMaskSpatialObject::GetAxisAlignedBoundingBoxRegion()
> that computes the minimum axis aligned bounding box of a 3D binary image.
>
> ImageMomentsCalculator can help you with moments, CG etc.
>
> An appropriate class to add methods to compute volume, perimeter,
> surface area etc may be theImageMaskSpatialObject class . You could
> write them and put them back into ITK :)
>
> I don't think ITK has many CAD measurement methods.
>
>> Also, what is the recommended approach for making greyscale measures
>> of regions defined by a connected component image?
>>
>> Thanks
>>
>> Richard
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>>
>>
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-- 
Gaetan Lehmann <gaetan.lehmann at jouy.inra.fr>
Tel: +33 1 34 65 29 66
Biologie du Développement et de la Reproduction
INRA de Jouy-en-Josas (France)
Web: http://voxel.jouy.inra.fr