[Insight-users] using Mutual Information

[Luis Ibanez]

Hi Jose,


Happy New Year !


The registration framework in ITK computes everything
in physical espace, not in pixel space.



1) Are your images 2D ?


2) Are the (x,y) coordinates regular ?
    that is, can they be simply computed as

         (Ox + i * Sx ,  Oy + j * Sy )

    where Ox,Oy is the origin of the image,
    Sx,Sy are the interpixel spacing, and i,j
    are the indices of a particular pixel.



3) Why do you encode in the Z coordinate the
    intensity of the image before normalization ?
    This sounds a bit like an elevation grid....



4) Yes, you can use ITK for registering images
    that have a reduced overlapping region.



We *strongly encourage* you to read the chapter
on image resampling and the chapter on image
registration from the ITK Software Guide


    http://www.itk.org/ItkSoftwareGuide.pdf


- Section 6.7 "Geometric Transformations", pdf-page 199.
- Chapter 8   "Image Registration", pdf-page  241-340



   Please let us know if you have further questions,



     Thanks



       Luis



----------------------------
José Santamaría López wrote:
> Hi Luis,
> 
>   after of all...happy new year :-)
> I'm thinking on applying the mutual information
> approach as metric for imagen registration in
> a new problem.
> 
> My doubt is if the registration framework needs
> to work with physical space instead on pixel
> space, that is, I have two gray scale images
> at given resolution where its intensity values
> indicates some feature. Each pixel value also
> has a (x,y,z) world coordenate value, where
> the z component references to the former normalized
> pixel intensity.
> 
> The two images only share a partial common area with
> similar structure of gray scale pixels at their whole
> images. My intention should be to obtain a good
> pre-matching between those similar areas from
> both images by means a rigid body registration.
> 
> Could I make use of ITK Software to develop a
> solution for such problem?
> 
> 
> Thanks.
> 
> Jose
> 
> 
>