[Insight-users] Label Image question again...

[Anja Ende]

Hi Richard,

Yes, the region conversion is where I am stuck!

The points indeed do represent the vertices of the 2D polygon and
drawing a line through these points would give the shape.

Cheers,
Anja

2008/5/20 Richard Beare <richard.beare at gmail.com>:
> Hi,
>
> I attempted to answer this before, but obviously wasn't clear enough.
>
> The critical step seems to be the point to region conversion, which
> depends on the meaning of the user defined points. So are these points
> corners of a polygon? i.e. if you drew lines in an image (assuming 2D)
> from the point 1 to 2, 2 to 3 ... and finally n to 1 to give you a
> closed shape, would those lines represent the outline of the shape you
> are interested in?
>
> On Tue, May 20, 2008 at 8:55 PM, Xabier Artaechevarria Artieda
> <xabiarta at unav.es> wrote:
>> You can use:
>>
>> http://www.itk.org/Doxygen34/html/classitk_1_1SpatialObjectToImageFilter.html
>>
>> However, that will give you separate points, not a contiguous irregular
>> binary shape.
>> I do not know of any filter that can do that, it might be that you have to
>> implement this.
>>
>> Maybe somebody can help here?
>>
>> --
>> Xabier Artaechevarria
>> Cancer Imaging Laboratory
>> Centre for Applied Medical Research
>> www.cima.es
>>
>>
>>
>> Anja Ende <anja.ende at googlemail.com> ha escrito:
>>
>>> Hi,
>>>
>>> Actually spoke too soon! Do not see how I can convert this
>>> BlobSpatialObject to a binary itk::Image.
>>>
>>> It seems to be very difficult to be able to create a binary image by
>>> hand unless you use one of the itk filters...
>>>
>>> Cheers,
>>> Anja
>>>
>>> 2008/5/20 Anja Ende <anja.ende at googlemail.com>:
>>>>
>>>> Hi Xabi,
>>>>
>>>> Thanks for your reply!
>>>>
>>>> 4. So, now the problem is how to compute a binary region from those
>>>> points. What do you want exactly? Is it the bounding box? You can get
>>>> this with SpatialObjects (BlobSpatialObject).
>>>>
>>>> I actually need the shape that the points represent. It is not really
>>>> a rectangle but an irregular shape. I think the BlobSpatialObject
>>>> might be the thing that I need as it seems to be able to represent any
>>>> amorphous shape. I will give this a shot now!
>>>>
>>>> Cheers,
>>>> Anja
>>>>
>>>> 2008/5/20 Xabier Artaechevarria Artieda <xabiarta at unav.es>:
>>>>>
>>>>> Hi Anja,
>>>>>
>>>>> Let's see if I can help a bit with some points.
>>>>>
>>>>> 1. The article you mentioned is an Insight Journal contribution.  As
>>>>> such, it
>>>>> includes the code needed to reproduce the results. You need this  code,
>>>>> which
>>>>> you can find in
>>>>>
>>>>> http://insight-journal.org/InsightJournalManager/view_reviews.php?pubid=176.
>>>>> This includes the LabelImage class, the classes to convert different
>>>>> images
>>>>> to a LabelMap, and so on.
>>>>>
>>>>> 2. At least that I know, there is no straighforward way to create a
>>>>> LabelImage based on a user defined contour. What you need, though, is a
>>>>> LabelMap.
>>>>>
>>>>> 3. You must do it in two steps. First convert your points to binary
>>>>> image,
>>>>> and then this image to a label map. You can convert a Binary image to a
>>>>> label map easily with the itkBinaryImageToBinaryMapFilter.
>>>>>
>>>>> 4. So, now the problem is how to compute a binary region from those
>>>>> points.
>>>>> What do you want exactly? Is it the bounding box? You can get this with
>>>>> SpatialObjects (BlobSpatialObject).
>>>>>
>>>>> Hope that helps,
>>>>> Xabi
>>>>>
>>>>> --
>>>>> Xabier Artaechevarria
>>>>> Cancer Imaging Laboratory
>>>>> Centre for Applied Medical Research
>>>>> www.cima.es
>>>>>
>>>>>
>>>>>
>>>>> Anja Ende <anja.ende at googlemail.com> ha escrito:
>>>>>
>>>>>> Hi all,
>>>>>>
>>>>>> I am really frustrated at my inability to achieve this and hope
>>>>>> someone can help me with a few lines of code on how to achieve this:
>>>>>>
>>>>>> - I have an itk::Image object and a set of points in the image
>>>>>> coordinates that represent a ROI.
>>>>>> - I cannot for saving my life figure out how to generate a LabelObject
>>>>>> based on this.... I have had some help when I asked this question
>>>>>> before but there seems to be a disconnect somewhere and I am missing a
>>>>>> step.
>>>>>>
>>>>>> I guess I have to figure out a way to render the region defined by
>>>>>> these points into another image and somehow use this image as a mask
>>>>>> on the original image. However, I just do not know how to achieve this
>>>>>> with the ITK classes. The document entitled "Label Object
>>>>>> representation and manipulation with ITK" somehow (I think) assumes
>>>>>> that the LabelImage is easily created, but I am finding it very
>>>>>> difficult to actually create this LabelImage!
>>>>>>
>>>>>> Is there any documentation on how one can create a LabelImage based on
>>>>>> a user defined contour???
>>>>>>
>>>>>> Please help!
>>>>>>
>>>>>> --
>>>>>> Cheers,
>>>>>>
>>>>>> Anja
>>>>>> _______________________________________________
>>>>>> Insight-users mailing list
>>>>>> Insight-users at itk.org
>>>>>> http://www.itk.org/mailman/listinfo/insight-users
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> ----------------------------------------------------------------
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>>>>>
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>>>>> Insight-users mailing list
>>>>> Insight-users at itk.org
>>>>> http://www.itk.org/mailman/listinfo/insight-users
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Cheers,
>>>>
>>>> Anja
>>>>
>>>
>>>
>>>
>>> --
>>> Cheers,
>>>
>>> Anja
>>>
>>
>>
>>
>> ----------------------------------------------------------------
>> Este mensaje ha sido enviado desde https://webmail.unav.es
>>
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>



-- 
Cheers,

Anja