[vtkusers] Image Histograms

[Tobias Wissmüller]

Hi,

I am having problems with vtkImageAccumulate and computing a histogram with
it. I have a simple grey value image and fed it to vtkImageAccumulate. I
want to put the histogram in a vtkXYPlotActor or something similar.
The code I have so far, assuming that image is my vtkImageData I read from a
file:

vtkImageAccumulate* accu = vtkImageAccumulate::New();
vtkImageMapper* mapper = ...
vtkXYPlotActor* actor = ...
vtkRenderer* renderer = ...
vtkRenderWindow* window = ...
vtkRenderWindowInteractor* interactor = ...

accu -> SetInput(image);
mapper -> SetInput(accu->GetOutput());
actor -> SetMapper(mapper);
renderer -> AddActor(actor);
window -> AddRenderer(renderer);
interactor -> SetRenderWindow(window);

window -> Render();
interactor -> Start();

When I run it there is this error message from vtkXYPlotActor: Nothing to
plot?!

Does anyone have an idea? Thanks?

Bye,
Tobi