[Insight-users] RescaleIntensityImageFilter doesn't respect user-set InputMinimum/Maximum

[Mathias Seitel]

Hello,

I also think it's convenient to have a rescale intensity filter which 
allows for both automatic detection and manual setting of the input 
image range. I've recently written a class itk::MapIntensityImageFilter 
which is similar to RescaleImageIntensityFilter, but offers two 
operation modes:

Range: InputMinimum and InputMaximum have to be specified manually

MinMax: InputMinimum and InputMaximum will be detected with a 
StatisticsImageFilter

In my application, this filter helps to reduce memory consumption and 
processing time, since I need to switch the mapping behaviour during 
runtime.

Please let me know if you are interested in the code so I could post it.

Mathias


Luis Ibanez wrote:

> 
> Hi Zach,
> 
> This looks like a bug....
> 
> Actually there shouldn't be any SetInputMinimun and
> SetInputMaximum methods in this filter...
> 
> 
> In any case, the filter that you want is the
> 
>      IntensitityWindowImageFilter
> 
> http://www.itk.org/Insight/Doxygen/html/classitk_1_1IntensityWindowingImageFilter.html 
> 
> 
> 
> where you can select the input and output, minimum
> and maximum.
> 
> 
> Regards,
> 
> 
>     Luis
> 
> 
> ---------------------
> Zachary Pincus wrote:
> 
>> Hello,
>>
>> The RescaleImageIntensityFilter provides methods to set the 
>> "InputMinimum" and "InputMaximum" values. This provision would lead 
>> one to believe that after setting these values, the rescaling will be 
>> from the user-defined input range to the user-defined output range.
>>
>> However, in actuality, these user-defined values are ignored, and 
>> re-set to the minimum and maximum pixel values in the input image. 
>> (itkRescaleIntenistyImageFilter.txx, line 88.)
>>
>> I'm trying to think of a good mechanism whereby the user can take 
>> control of these values.
>> Should the filter automatically note on setting the InputMix/Max that 
>> the user has requested this, and then not overrule them? Then how 
>> would the user turn this off?
>>
>> Perhaps there should be additional methods to tell the class to use 
>> the current values or recalculate them? This seems a bit confusing, 
>> though.
>>
>> Any thoughts?
>>
>> Zach Pincus
>>
>> Department of Biochemistry and Program in Biomedical Informatics
>> Stanford University School of Medicine
>>
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> 
> 
> 
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-- 
Dipl.-Inf. (FH) Mathias Seitel
Fraunhofer Gesellschaft         Phone: +49-6151-155 484
Institute for Computer Graphics Fax: +49-6151-155 559
Fraunhoferstr. 5                mailto: mathias.seitel@igd.fhg.de
D-64283 Darmstadt, Germany      www: http://www.igd.fhg.de/igd-a7