[vtkusers] Got some problems on MIP

[=?GB2312?B?/Yj9iA==?=]

HI, all

I'm working a project using VTK, and using maximum intensity projection to
display a DICOM image data(3D). I saw some examples(including some official
examples ) just like following :

vtkSmartPointer<vtkPiecewiseFunction> volumeScalarOpacity =
vtkSmartPointer<vtkPiecewiseFunction>::New();
double range[2];
originImageData->GetScalarRange(range);
double level = 0.5 * (range[1] + range[0]);
double window = range[1] - range[0];

volumeScalarOpacity->AddPoint(level - window/2, 0.0);
volumeScalarOpacity->AddPoint(level + window/2, 1.0);

Almost examples are trying to adjust opacity to get the MIP visual effect.
But when I turn the image format from USHORT to UCHAR. that means the
maximum intensity decreasing  to the 255. So the luminance of the
projection image also goes down.

Therefore, i guess that adjust the window width/window level maybe more
reasonable for MIP not to adjust the opacity ?
but i can not find the window width/level function. don't know how to use .

Please help.
Thank U.

-- 
>From Ryuu
Nothing but a MADAO！
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