[Insight-users] Creating a spatial object from a binary image

[Vincent Chu]

Hi Luis,

The quick and dirty fix doesn't seem to work.  The ValueAt function seems
to call IsInside indirectly, resulting an infinite recursion.  Any
suggestion around this?

Thanks,

Vincent

On Thu, 3 Jun 2004, Luis Ibanez wrote:

>
> Hi Vincent,
>
> Thanks for pointing this out.
>
> This looks like a bug in the ImageSpatialObject.
>
> We just entered as Bug # 909
> http://www.itk.org/Bug/bug.php?op=show&bugid=909&pos=0
>
>
> The "IsInside()" method is simply checking if
> the point is inside the bounding box of the image.
>
> As a quick and dirty fix please do the following:
>
> 1) Go to
>
>     Insight/Code/SpatialObjects/
>                  itkImageSpatialObject.txx
>
>
> 2) Search for lines 68 to 78 where the methods
>     "IsInside()" is defined.
>
> 3) Replace the current content of "IsInside()" with
>     a delegation like
>
>       {
>       this->ValueAt( point, value, depth, name );
>       return (value != 0);
>       }
>
>
> For a long term solution we probably need to
> add a explicit class:
>
>         ImageMaskSpatialObject
>
>
> with an IsInside() methods as the one you just
> implemented.
>
>
>
> Please let us know if you find any other problems,
>
>
>     Thanks
>
>
>       Luis
>
>
> -------------------
> Vincent Chu wrote:
> > Hi Luis,
> >
> > Thanks for the reply.  I tried SetImage() to an image whose pixel type is
> > unsigned char, and each pixel has value either 0 or 255.  However,
> > isInside(PointType x) seems to return true regardless of whether x is a
> > point where the pixel value is 0 or 255.  This is what I have in code:
> >
> > /////////////////////////////////////////////////////////////////////
> >
> > typedef itk::Point<double,3> Point;
> >   Point insidePoint;
> >   insidePoint[0]=182;
> >   insidePoint[1]=256;
> >   insidePoint[2]=15;
> >   if( imageSO->IsInside(insidePoint) )
> > 	  std::cout << insidePoint << " is inside the image." <<
> > std::endl;
> >   double returnedValue;
> >   imageSO->ValueAt(insidePoint,returnedValue);
> >   std::cout << "ValueAt(" << insidePoint << ") = " << returnedValue <<
> > std::endl;
> >   insidePoint.Fill(1);
> >   if( imageSO->IsInside(insidePoint) )
> > 	  std::cout << insidePoint << " is inside the image." <<
> > std::endl;
> >   imageSO->ValueAt(insidePoint,returnedValue);
> >   std::cout << "ValueAt(" << insidePoint << ") = " << returnedValue <<
> > std::endl;imageSO->ValueAt(insidePoint,returnedValue);
> >
> > //////////////////////////////////////////////////////////////////////////
> >
> > And I get the following output:
> >
> > 182  256  15 is inside the image.
> > ValueAt(182  256  15) = 255
> > 1  1  1 is inside the image.
> > ValueAt(1  1  1) = 0
> >
> > Did I setup something wrong?
> >
> > Thanks,
> >
> > Vincent
> >
> >
> >
> >
> > On Thu, 3 Jun 2004, Luis Ibanez wrote:
> >
> >
> >
> >>Hi Vincent,
> >>
> >>You are in the right track,
> >>the class to use is the:
> >>ImageSpatialObject.
> >>http://www.itk.org/Insight/Doxygen/html/classitk_1_1ImageSpatialObject.html
> >>
> >>
> >>Just connect your image mask to the ImageSpatialObject
> >>using its "SetImage()" method.
> >>
> >>There is no overload for doing this. At the end,
> >>the spatial object just need to answers the queries
> >>for whether a pixel is "inside" of the object (your
> >>image mask in this case) or not. What the Spatial
> >>object is doing is simply delegating the quiery to
> >>the underlying image mask that you provided.
> >>
> >>
> >>Please let us know if you have further questions,
> >>
> >>
> >>    Thanks
> >>
> >>
> >>      Luis
> >>
> >>
> >>----------------
> >>Vincent Chu wrote:
> >>
> >>
> >>>Hi,
> >>>
> >>>I am new to ITK and would like to perform registration between two images.
> >>>The region of interest has arbitrary shapes, and I previously read from
> >>>the list that we can use SetMovingImageMak() and SetFixedImageMask() in
> >>>ImageToImageMetrics to set the region in which the metrics will be
> >>>computed.  However, those two methods expect spatial objects as parameter,
> >>>and I have trouble converting a binary image into a spatial object.  I
> >>>have tried ImageSpatialObject, but the entire binary image would be
> >>>created as one big spatial object.  Which class should I use instead?
> >>>
> >>>Thanks,
> >>>
> >>>Vincent
> >>>_______________________________________________
> >>>Insight-users mailing list
> >>>Insight-users at itk.org
> >>>http://www.itk.org/mailman/listinfo/insight-users
> >>>
> >>
> >>
> >>
> >>
> >
>
>
>
>