[IGSTK-Users] How to get the ImageSpatialObject from an ImageSpatialObjectRepresentation

[Vincent Gratsac]

Hi Luis,

Thank you for your help.

The solutions you described here seems to be a right way to do.
However, this means that we still have to store the corresponding 
ImageSpatialObject for each ImageObjectRepresentation, isn't it ?

I don't know where to log it as a bug. Could you tell me how to do ?

Vincent.

Luis Ibanez wrote:
>
>
> Hi Vincent,
>
>
> Thanks for pointing this out.
>
>
> What we are planning to do here is the following:
>
> 1) Views, in response to picking events will throw
>    IGSTK PointEvents, that will contain both a Point
>    and a reference to a coordinate system (the one
>    of the View).
>
> 2) You will be able to request the Transform between
>    the View CoordinateSystem and the ImageSpatialObject
>    pixel data coordinate system.
>
> 3) With the Transform you will get from (2), you will
>    be able to convert the point from the View coordinate
>    system to the ImageSpatialObject pixel data coordinate
>    system
>
> 4) Once you have the point in image space, you will be
>    able to map it to pixel indices and access (read only)
>    pixel data.
>
>
> Pieces (1),(3) and (4) need to be implemented.
> Piece (2) is currently functional
>
>
> Could you please log a bug, for this topic ?
>
> You could describe it as "fixing the coordinate system
> framework for picking events".
>
> ... or something along those lines...
>
>
> BTW: Breaking the encapsulation of the ImageObjectRepresentation
>      is probably not the best way to solve this issue.
>
>
>
>    Thanks
>
>
>       Luis
>
>
>
> ---------------------
> Vincent Gratsac wrote:
>> Hi all,
>>
>> First of all, thanks for the great effort of the IGSTK team to bring 
>> us this new release !
>>
>> I did not receive any answer to my last mail about how to get the 
>> ImageSpatialObject from an ImageObjectRepresentation.
>>
>> Did you understand my problem, and do you think that adding a 
>> RequestGetImageSpatialObject() method to the 
>> ImageObjectRepresentation class would be possible ?
>>
>> Vincent
>>
>>> Hi all,
>>>
>>> I'm currently working on slicing of displayed objects by giving a 
>>> picked point.
>>> The NeedleBiopsy example is helpful to learn how to do that !
>>> Here is my problem : my software can display some 
>>> ObjectRepresentations for more than one SpatialObjects, but I'm not 
>>> able to know to which ImageSpatialObject an 
>>> ImageSpatialObjectRepresentation is related.
>>>
>>> This is a problem when we try to convert a physical point to image 
>>> indexes ( that's why I submitted the idea to add a 
>>> ResliceToPhysicalPoint method in the 
>>> ImageSpatialObjectRepresentation class).
>>>
>>> This is also a problem if the transformation between one of the 
>>> ImageSpatialObjects and the View object differs from Identity. In 
>>> this case, I need to get this transformation and multiply its 
>>> inverse to the picked point's coordinates, in order to express the 
>>> picked point's coordinates in the ImageSpatialObject coordinate 
>>> system. Next, I will have to convert the physical point to image index.
>>>
>>> To conclude, I found some cases in which getting the 
>>> ImageSpatialObject from an ImageSpatialObjectRepresentation is very 
>>> useful. Is there a way to do it , or would it be unsafe to add such 
>>> a method ?
>>>
>>> Vincent
>>
>>

-- 
Vincent Gratsac
----------------------------------------------------
Unité/Projet VisAGeS U746
INSERM/INRIA/CNRS/U. de Rennes I
IRISA
Campus de Beaulieu, 35042 Rennes Cedex, France

Ph:  +33 (0) 2 23 23 49 20/ Fax: +33/0 2 99 84 71 71
email: Vincent.Gratsac at irisa.fr
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