[Insight-developers] Image Orientation Progress(2)

[Stephen R. Aylward]

One thought...

If image allows for origin, scaling (spacing), and orientation, then 
this API will begin to parallel the spatialObjects API.   There are 
several notable differences, and I do NOT suggest that we attempt to 
merge these constructs, but looking at them both might be useful.

In particular, since we are essentially now supporting a transform 
within an image, do we want to do like the rest of the transforms and 
have a center of rotation and parameters?  Center of rotation would 
default to the origin and not change behaviour by default.   The 
motivation is that Lydia (just me trying to share the blame :) ) and 
others agree that a center of rotation is essential to registration. 
With these additions, image registration could be specified 100% 
internal to the image - via its transform.   It becomes a spatial object 
of sorts.

I don't feel strongly about this in any way, but it should be considered 
now rather than later....

Stephen

Bill Lorensen wrote:

> Simon,
> Not yet. I have not addressed the patient coordinate naming conventions 
> yet. These changes are independent of that.
> And vtk is another issue...
> 
> Bill
> 
> At 03:38 PM 3/12/2005, Simon Warfield wrote:
> 
>> Lorensen, William E (Research) wrote:
>>
>>> Folks,
>>> Some more progress on the image orientation upgrade.
>>>
>>> I have been worried about performance of the PhysicalPointToIndex and 
>>> other related transformations in itkImage. I have created a subclass 
>>> of image called itkOrientedImage that uses the direction cosines to 
>>> convert between physical space and vice versa. itkImageBase still 
>>> keeps the direction cosines but does not use them for conversion 
>>> between physical and index spaces. The only perfomance hit for Imnage 
>>> may come from making the transformation methods virtual.
>>>
>>> (I know Stephen, this is deja vu all over again when we first did 
>>> image.)
>>>
>>> This compromise will permit applications to treat the orientation if 
>>> desired while allowing other apps to trade-off performance if all 
>>> images are of the same ilk.
>>>
>>> I am still doing this in my local checkout. I'd appreciate comments.
>>>
>>
>> I would like to try it out.
>> I wonder about the interaction with VTK.  I would like to use VTK to 
>> render images oriented correctly. Do you need to have an 
>> OrientedImageToVTKImageFilter ?
>>
>>> Bill
>>> _______________________________________________
>>> Insight-developers mailing list
>>> Insight-developers at itk.org
>>> http://www.itk.org/mailman/listinfo/insight-developers
>>>
>>
>>
>> -- 
>> Simon K. Warfield, Ph.D. warfield at bwh.harvard.edu Phone:617-732-7090
>> http://www.spl.harvard.edu/~warfield           FAX:  617-582-6033
>> Associate Professor of Radiology,          Harvard Medical School
>> Director, Computational Radiology Laboratory
>> Thorn 329, Dept Radiology,  Brigham and Women's Hospital 75 Francis 
>> St, Boston, MA, 02115
>> MA 280, Dept Radiology, Children's Hospital Phone: 617-355-4566
>>
>> _______________________________________________
>> Insight-developers mailing list
>> Insight-developers at itk.org
>> http://www.itk.org/mailman/listinfo/insight-developers
> 
> 
> _______________________________________________
> Insight-developers mailing list
> Insight-developers at itk.org
> http://www.itk.org/mailman/listinfo/insight-developers