[ITK-users] Pixel operations on subsets of label objects

[Pol Monsó Purtí]

If I understood correctly, you have uniform greyscale blobs whose value
matters and you want to extract one slice from each blob to do something
with them, right?

It wasn't clear to me wether each blob had an uniform greyscale value or if
instead you have 'islands' on the image with various greyscale data in
them.

In the first case, I don't know if there's a way to run
connectedComponentsFilter so that it doesn't change the objects labels.

>From the top of my head:

In the first case, you could threshold the image to the greyscale value to
get the blob you want.

In the second case, you could binarize the image, run connected components,
select the one you want and then use the maskImageFilter on the original
volume to isolate one object. Then use ExtractimageFilter to extract a 2d
slice of the isolated blob and do the operations you want. If you want to
assemble it back, use the RegionOfInterest instead, I guess.

>From the top of my head, probably not the best,
Pol

2015-04-18 20:43 GMT+02:00 <cervellone at gmail.com>:

> Thanks for the reply
>
> I am handling 3d voxel data.  Starting from gray levels I want to run a
> connected components but  keep the gray level data and iterate over the
> label map,
> The property I am interested in is not in the shape label map, nor in the
> statistics label map.
>
> I would like to compute the threshold for every 2d slice of the 3d label
> object separately. For this I would need to extract the pixels of the label
> object and use the extract slice image filter on it. Any idea how this can
> be done ?
>
>
> Thanks jp
>
>
> On Friday, April 17, 2015, Pol Monsó Purtí <lluna.nova at gmail.com> wrote:
>
>> Hello jp,
>>
>> How do you distinguish which objects are you interested in and what
>> operations do you want to perform?
>>
>> Maybe this example is helpful to you:
>> http://www.itk.org/Wiki/ITK/Examples/ImageProcessing/BinaryImageToShapeLabelMapFilter
>>
>> HTH,
>>
>> Pol
>>
>> 2015-04-17 20:08 GMT+02:00 jp <cervellone at gmail.com>:
>>
>>> Dear all,
>>> I would like to iterate over the label object and perform pixel
>>> operations
>>> of a subset of a label object.
>>> Currently fail to see how i can set up the label manipulation tools of
>>> itk
>>> to achieve this
>>>
>>> Thank you
>>>
>>> jp
>>>
>>>
>>>
>>>
>>>
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