// Function: Calculate en render Histogram in window
public void renderHistogram(vtk.vtkImageData VoxelData)
{
// Get size of histogram window
int[] size = renHist.GetSize();
width = size[0]; height = size[1];
//Setup parameters histogram Accumulate Filter
numBins = width / 2;
inputRange = VoxelData.GetScalarRange();
double origin = inputRange[0];
double spacing = 1.0 * (inputRange[1] - origin) / numBins;
// Setup Accumulate filter
vtk.vtkImageAccumulate accumulate = new vtk.vtkImageAccumulate();
accumulate.SetInput(VoxelData); //Get input voxeldata
accumulate.SetComponentExtent(0, numBins - 1, 0, 0, 0, 0);
accumulate.SetComponentOrigin(origin, 0.0, 0.0);
accumulate.SetComponentSpacing(spacing, 1.0, 1.0);
// Make Data object from Accumulated object
data = accumulate.GetOutput();
data.Update();
// Initialize first and last point of the transferfunction.
npoints = 2;
pointsx[0] = 0; pointsy[0] = 0;
pointsx[1] = width - 1; pointsy[1] = height - 1;
pointsc[0] = 1; pointsc[1] = 1;
// Draw the histogram in a canvas and add the transferfunction to it
drawhisto();
drawcurve();
// Create a color table
vtk.vtkColorTransferFunction colorTransferFunction = new vtk.vtkColorTransferFunction();
for (int i = 0; i < 14; i++)
{
colorTransferFunction.AddRGBPoint(i, colortable[i, 0], colortable[i, 1], colortable[i, 2]);
}
// Use the color table to color the histogram window objects
vtk.vtkImageMapToColors sColors = new vtk.vtkImageMapToColors();
sColors.SetInputConnection(canvas.GetOutputPort());
sColors.SetLookupTable(colorTransferFunction);
// Convert the histogram image to a histogram imagemap
vtk.vtkImageMapper histmap = new vtk.vtkImageMapper();
histmap.SetInputConnection(sColors.GetOutputPort());
histmap.RenderToRectangleOn();
histmap.SetColorWindow(256);
histmap.SetColorLevel(127);
// Create the actor needed to draw the histogram image
vtk.vtkActor2D imageactor = new vtk.vtkActor2D();
imageactor.SetMapper(histmap);
imageactor.SetPosition(0, 0); // Fit the histogram to the window
imageactor.SetPosition2(1, 1);
// Add the Histogram Image Render to the window object
ren1.AddActor(imageactor);
ren1.SetViewport(0, 0, 1, 1); // Fit the histogram to the window
renHist.AddRenderer(ren1);
// Add a Window (mouse) interactor to the window
iren.SetRenderWindow(renHist);
// Add mouse events to the window
iren.RemoveObserver((uint)vtk.EventIds.LeftButtonPressEvent);
iren.AddObserver((uint)vtk.EventIds.LeftButtonPressEvent, new vtk.vtkDotNetCallback(LeftButtonPress));
iren.RemoveObserver((uint)vtk.EventIds.LeftButtonReleaseEvent);
iren.AddObserver((uint)vtk.EventIds.LeftButtonReleaseEvent, new vtk.vtkDotNetCallback(LeftButtonRelease));
iren.RemoveObserver((uint)vtk.EventIds.MouseMoveEvent);
iren.AddObserver((uint)vtk.EventIds.MouseMoveEvent, new vtk.vtkDotNetCallback(MouseMove));
iren.RemoveObserver((uint)vtk.EventIds.RightButtonPressEvent);
iren.AddObserver((uint)vtk.EventIds.RightButtonPressEvent, new vtk.vtkDotNetCallback(RightButtonPress));
iren.RemoveObserver((uint)vtk.EventIds.MiddleButtonPressEvent);
iren.AddObserver((uint)vtk.EventIds.MiddleButtonPressEvent, new vtk.vtkDotNetCallback(MiddleButtonPress));
// Set the (display) update rate of the histogram
iren.SetStillUpdateRate(5);
iren.SetDesiredUpdateRate(5);
// Initialize interactor and render histogram
iren.Initialize();
renHist.Render();
// Debug output
info = "Histogram is created \r\n";
}