[Insight-users] orientation of images - origin

[Luis Ibanez]

Hi Carmen,

There are no visualization functionalities in ITK.

How the images are displayed is not related to ITK.

This is something that you have to manage in your
visualization code, or at least in the transition
between ITK images and the representation that you
use for visualization.

The help you can get from ITK is related to the
conversion of indexes to physical coordinates, but
it is up to your standard file format to associate a
coordinate system to the anatomical orientation of
the image.  There is no warranty that +Z is going
to be superior, or that +Y is going to be the right
side of the patient.

Reading data from RAW files doesn't help at all in
this process since the interpretation of the data
is entirely up to you. That's one of the reasons for
discouraging the use of raw files for medical imaging.

The convention of having the origin of coordinates
displayed at the top left corner of the image is
a legacy of raster graphics  and is very counter-
intuitive for performing operations such as image
registration.

You may want to take a look at the ImageViewer demo
application in InsightApplications/ImageViewer which
implements a reasonable approach for displaying
medical images.


   Regards,


     Luis



-----------------------

Carmen Olmos wrote:

> I don't know if Sandhya has the same problem I have. My raw data should 
> be displayed taking as origin the left-down corner instead of the 
> left-up corner (as by default in ITK) I wonder if there is a way to read 
> my data specifying the origin.
>  
> Thanks.
> Carmen
>