[Insight-users] about initial level set

[Sandarak]

Hello Ivan!

I've feed my image (255 for object and 0 for background) first to:

itkIntensityWindowingImageFilter with settings:

->SetOutputMinimum( 1024 );
->SetOutputMaximum( -1024 );

This has photographic negated my image to  0 for object and 255 for background

then I've run:

itkRescaleIntensityImageFilter with:

->SetOutputMinimum(-1);
->SetOutputMaximum(1);

As an output I have image with -1 for inside and 1 for outside.

This works well as input for level set filters like geodesic.

Regards

Michal Postrozny



> Hi all,

> The same thing happens to me with intensity 255 for the object and 0 for the
> background. Is this the correct behaviour? In the software guide the
> level-set function is positive inside and negative outside the zero
> level-set. Shouldn't this be consistent with the fact that the foreground
> (object) value is higher than the background value?

> Thanks in advance

> Ivan


>> -----Mensaje original-----
>> De: insight-users-bounces+imacia=vicomtech.es at itk.org 
>> [mailto:insight-users-bounces+imacia=vicomtech.es at itk.org] En 
>> nombre de Michal Postrozny
>> Enviado el: jueves, 16 de junio de 2005 23:00
>> Para: luis.ibanez at kitware.com; insight-users at itk.org
>> Asunto: Re[3]: [Insight-users] about initial level set
>> 
>> 
>> Hello Luis,
>> 
>> After setting intensity of -1 for the segmented object 
>> (inside) and 1 for background (outside) everything works 
>> fine. Sorry for bothering you.
>> 
>> Regards
>> 
>> Michal Postrozny
>> 
>> > Hello Luis,
>> 
>> > You have said that there is no need to do anything with the binary
>> > image, just feed it to the level set filter. I've tried to 
>> feed binary 
>> > image with intensities of 255 for segmented object and zero for 
>> > background to the GeodesicActiveContourLevelSetImageFilter. 
>> But this 
>> > doesn't work. I must be missing something important. After applying
>> > ApproximateSignedDistanceMapImageFilter to the binary image and 
>> > feeding it to the geodesic everything works fine. But 
>> > ApproximateSignedDistanceMapImageFilter is rather slow, so 
>> if it was 
>> > possible to feed binary image directly to geodesic it would 
>> be great. 
>> > How can I achieve this?
>> 
>> > Thanks in advance
>> 
>> > Michal Postrozny
>> 
>> 
>> 
>> 
>> >> Yixun,
>> 
>> 
>> >> Don't need to do anything particular.
>> 
>> >> You can feed your binary image directly as input level set.
>> 
>> 
>> >> Regards,
>> 
>> 
>> >>     Luis
>> 
>> 
>> >> ----------------
>> >> Yixun Liu wrote:
>> 
>> >>> Hi,
>> >>>  
>> >>> I have a  segmented image represented by binary image. I 
>> want to use 
>> >>> level set to refine the segmentation based on the 
>> segmented image. 
>> >>> How to generate a initial level set based on this binary image?
>> >>>  
>> >>> Best regards,
>> >>>  
>> >>> Yixun Liu
>> >>> 
>> >>> 
>> >>> 
>> --------------------------------------------------------------------
>> >>> ----
>> >>> 
>> >>> _______________________________________________
>> >>> Insight-users mailing list
>> >>> Insight-users at itk.org 
>> >>> http://www.itk.org/mailman/listinfo/insight-users
>> 
>> 
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