[Insight-users] Filter plans

[Gaëtan Lehmann]

Le Tue, 17 Oct 2006 21:18:16 +0200, Prename Surname  
<bsd.diverse at gmail.com> a écrit:

> aha i see...
> Yes, of course i know this is simple, but starting simple is always the  
> way
> to go :)

sure

>
> I think maybe you have misunderstood what i want to do. I dont want to  
> make
> a RGB image, i just want to combine 3 different binary mask images into a
> single grayscale mask image with values 0,1,2,3 (0=background, 1=gm,
> 2=wm,3=wm)
> If i just manage this i can port it to vtk no problem.
> So i just wanted to create a composite filter to do this for me.
> Do you see what i mean?

Yes, I think :-)
This mean you are sure that the object in an image is never overlapping  
with the objects in the other images. Is it the case ?
If yes, you can use ChangeLabelImageFilter to change the value of your  
background pixels to 0 (if it's not already the case), and the values of  
the foreground pixel to 1 in the first image, 2 in the second one, and 3  
in the last one. Finally, you can add your 3 images with  
NaryAddImageFilter to produce the image you want.
It can be quite boring to instantiate 4 filters to do that - perhaps  
that's the right time to implement a custom filter based on  
NaryFunctorImageFilter :-)

Gaetan

>
> Many regards :)
>
>
> 2006/10/17, Gaëtan Lehmann <gaetan.lehmann at jouy.inra.fr>:
>>
>>
>> Hi,
>>
>> Most of the time, the simple manipulation like this one can already be
>> done in ITK or VTK, so you shouldn't have to create a new filter to do
>> that :-)
>> However, we are always pleased to see someone motivated to develop some
>> new features for the toolkit, especially if he/she want to contribute  
>> that
>> code to the community. I'm pretty sure you'll find something useful to
>> code soon :-)
>>
>> To combine your 3 images, you can use ComposeRGBImageFilter (1), which
>> takes 3 input images and give you a RGB image.
>> However, I'm not sure you can pass the rgb image directly to vtk  
>> (perhaps
>> something to code :-)). You'll have to pass the 3 binary images in vtk
>> with ImageToVTKImageFilter, and compose the color image in vtk.
>>
>> Gaetan
>>
>> (1)  
>> http://www.itk.org/Doxygen/html/classitk_1_1ComposeRGBImageFilter.html
>>
>>
>>
>> Le Tue, 17 Oct 2006 19:56:04 +0200, Prename Surname
>> <bsd.diverse at gmail.com> a écrit:
>>
>> > Hello.
>> > I am beginning to feel a bit more at home in itk/vtk now. There are
>> > still a
>> > zillion things to learn about it, but its getting a bit better. So  
>> now i
>> > have decided that i want to try and make my own filter to get more
>> > acquainted with the whole pipeline approach.
>> >
>> > I have read chapter 13 in the itksoftwareguide, and i have thought  
>> about
>> > a
>> > approach to make my filter. I was hoping some of you experts would  
>> tell
>> > me
>> > if i am completely off, or if my idea is okay.
>> > My situation is this:
>> > I have a greyscale volume consisting of 182 slices that are 182x218
>> > pixels
>> > of a brain.
>> > I have a mask of corresponding size with values 0 and 255 for the
>> > positions
>> > of greymatter
>> > I have a mask of corresponding size with values 0 and 255 for the
>> > positions
>> > of whitematter
>> > I have a mask of corresponding size with values 0 and 255 for the
>> > positions
>> > of CSF(brainfluid)
>> >
>> > Basically i want my filter to combine the 3 masks to a single image,  
>> so
>> > that
>> > i can visualize this image in vtk with different colors for  
>> greymatter,
>> > whitematter and CSF.
>> >
>> >
>> > Making a filter (lets call it masking)that subclasses
>> ImageToImageFilter,
>> > and then takes 2 input images and somehow combining them to a single
>> > image
>> > by just adding them together.
>> >
>> > I then want to make a compositefilter that actually makes a pipeline  
>> of
>> 2
>> > masking filters, taking first 2 masks, combining them in the masking
>> > filter,
>> > takes the output of this and combine it with the third mask using  
>> again
>> > the
>> > masking filter, and then outputting the final masked image.
>> >
>> > Does this sound  feasible, and more important is this a good approach?
>> > I hope for some feedback.
>> >
>> > Many regards and thank you
>>
>>
>>
>> --
>> Gaëtan Lehmann
>> Biologie du Développement et de la Reproduction
>> INRA de Jouy-en-Josas (France)
>> tel: +33 1 34 65 29 66    fax: 01 34 65 29 09
>> http://voxel.jouy.inra.fr
>>



-- 
Gaëtan Lehmann
Biologie du Développement et de la Reproduction
INRA de Jouy-en-Josas (France)
tel: +33 1 34 65 29 66    fax: 01 34 65 29 09
http://voxel.jouy.inra.fr