[vtkusers] Dataset Math Transfer?

[Charles Law]

Jianhua,

vtkImageMathematics can do log operations on images.

or you could use vtkImageLogarithmicScale.  It passes an image through a 
logarithmic sigmoidal function.  I use this filter to display frequency 
domain images which typically have very large ranges/outliers.

Charles.

At 04:17 PM 11/29/00 -0600, Jianhua Ma wrote:
>Hi Dear VTK users,
>I was wondering is there some way in the vtkStructuredPointsReader
>or vtkStructuredPointsFilter:x to do the Math transfer:f(x) say,
>if x >0 then extract Ln(x)? In other words, I want to obtain
>Ln(all StructuredPoints>0), because my original data has too big dynamic
>range(0, 4.964107E+9).It has laye values in very few point.
>I would use this method to compress original data for Scalar Visualization.
>  Any help would be appreciated.
>-Jianhua
>