#include <vtkSmartPointer.h>
#include <vtkImageData.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleImage.h>
#include <vtkRenderer.h>
#include <vtkImageActor.h>
#include <vtkBMPReader.h>
#include <vtkExtractVOI.h>

//测试图像：../data/lena.bmp
int main(int argc, char* argv[])
{

	vtkSmartPointer<vtkBMPReader>reader =
		vtkSmartPointer<vtkBMPReader>::New();
	reader->SetFileName("../lena.bmp");
	reader->Update();

	int dims[3];
	reader->GetOutput()->GetDimensions(dims);

	vtkSmartPointer<vtkExtractVOI> extractVOI =
		vtkSmartPointer<vtkExtractVOI>::New();
	extractVOI->SetInputConnection(reader->GetOutputPort());
        //就是提取出来中间的部分1/4`3/4
       extractVOI->SetVOI(dims[0] / 4., 3.*dims[0] / 4., dims[1] / 4., 3.*dims[1] / 4., 0, 0);
	extractVOI->Update();

	vtkSmartPointer<vtkImageActor> originalActor =
		vtkSmartPointer<vtkImageActor>::New();
	originalActor->SetInputData(reader->GetOutput());

	vtkSmartPointer<vtkImageActor> voiActor =
		vtkSmartPointer<vtkImageActor>::New();
	voiActor->SetInputData(extractVOI->GetOutput());

	double originalViewport[4] = { 0.0, 0.0, 0.5, 1.0 };
	double voiviewport[4] = { 0.5, 0.0, 1.0, 1.0 };

	vtkSmartPointer<vtkRenderer> originalRenderer =
		vtkSmartPointer<vtkRenderer>::New();
	originalRenderer->SetViewport(originalViewport);
	originalRenderer->AddActor(originalActor);
	originalRenderer->ResetCamera();
	originalRenderer->SetBackground(1.0, 1.0, 1.0);

	vtkSmartPointer<vtkRenderer> shiftscaleRenderer =
		vtkSmartPointer<vtkRenderer>::New();
	shiftscaleRenderer->SetViewport(voiviewport);
	shiftscaleRenderer->AddActor(voiActor);
	shiftscaleRenderer->ResetCamera();
	shiftscaleRenderer->SetBackground(1.0, 1.0, 1.0);

	vtkSmartPointer<vtkRenderWindow> renderWindow =
		vtkSmartPointer<vtkRenderWindow>::New();
	renderWindow->AddRenderer(originalRenderer);
	renderWindow->AddRenderer(shiftscaleRenderer);
	renderWindow->SetSize(900, 300);
	renderWindow->Render();
	renderWindow->SetWindowName("ExtractVOIExample");


	vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
		vtkSmartPointer<vtkRenderWindowInteractor>::New();
	vtkSmartPointer<vtkInteractorStyleImage> style =
		vtkSmartPointer<vtkInteractorStyleImage>::New();

	renderWindowInteractor->SetInteractorStyle(style);
	renderWindowInteractor->SetRenderWindow(renderWindow);
	renderWindowInteractor->Initialize();
	renderWindowInteractor->Start();

	return EXIT_SUCCESS;
}

基础知识就这样吧，图形绘制忽略掉==争取一周之内搞定~~