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

[Richard Beare]

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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>>>>
>>>
>>>
>>>
>>> --
>>> Cheers,
>>>
>>> Anja
>>>
>>
>>
>>
>> --
>> Cheers,
>>
>> Anja
>>
>
>
>
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