VTK_Learning__單顏色通道圖像合成彩色

1.三張灰度圖像合成彩色圖

我們可以提取彩色的圖像的各個顏色分量，那麼同樣也可以將灰度圖像合併成爲一個彩色圖像。VTK中提供vtkImageAppendComponents類來合成彩色圖像，其輸入需要提供三個灰度圖像。

下面實例：

#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL);
 
#include <vtkSmartPointer.h>
#include <vtkImageCanvasSource2D.h>
#include <vtkImageAppendComponents.h>
#include <vtkImageActor.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleImage.h>
 
int main()
{
	vtkSmartPointer<vtkImageCanvasSource2D> red =
		vtkSmartPointer<vtkImageCanvasSource2D>::New();
	red->SetScalarTypeToUnsignedChar();
	red->SetNumberOfScalarComponents(1);
	red->SetExtent(0, 100, 0, 100, 0, 0);
	red->SetDrawColor(0, 0, 0, 0);
	red->FillBox(0, 100, 0, 100);
	red->SetDrawColor(255, 0, 0, 0);
	red->FillBox(20, 40, 20, 40);
	red->Update();
 
	vtkSmartPointer<vtkImageCanvasSource2D> green =
		vtkSmartPointer<vtkImageCanvasSource2D>::New();
	green->SetScalarTypeToUnsignedChar();
	green->SetNumberOfScalarComponents(1);
	green->SetExtent(0, 100, 0, 100, 0, 0);
	green->SetDrawColor(0, 0, 0, 0);
	green->FillBox(0, 100, 0, 100);
	green->SetDrawColor(255, 0, 0, 0);
	green->FillBox(30, 50, 30, 50);
	green->Update();
 
	vtkSmartPointer<vtkImageCanvasSource2D> blue =
		vtkSmartPointer<vtkImageCanvasSource2D>::New();
	blue->SetScalarTypeToUnsignedChar();
	blue->SetNumberOfScalarComponents(1);
	blue->SetExtent(0, 100, 0, 100, 0, 0);
	blue->SetDrawColor(0, 0, 0, 0);
	blue->FillBox(0, 100, 0, 100);
	blue->SetDrawColor(255, 0, 0, 0);
	blue->FillBox(40, 60, 40, 60);
	blue->Update();
 
	vtkSmartPointer<vtkImageAppendComponents> appendFilter =
		vtkSmartPointer<vtkImageAppendComponents>::New();
	appendFilter->SetInputConnection(0, red->GetOutputPort());
	appendFilter->AddInputConnection(0, green->GetOutputPort());
	appendFilter->AddInputConnection(0, blue->GetOutputPort());
	appendFilter->Update();
 
	vtkSmartPointer<vtkImageActor> redActor =
		vtkSmartPointer<vtkImageActor>::New();
	redActor->SetInputData(red->GetOutput());
 
	vtkSmartPointer<vtkImageActor> greenActor =
		vtkSmartPointer<vtkImageActor>::New();
	greenActor->SetInputData(green->GetOutput());
 
	vtkSmartPointer<vtkImageActor> blueActor =
		vtkSmartPointer<vtkImageActor>::New();
	blueActor->SetInputData(blue->GetOutput());
 
	vtkSmartPointer<vtkImageActor> combinedActor =
		vtkSmartPointer<vtkImageActor>::New();
	combinedActor->SetInputData(appendFilter->GetOutput());
 
	// Define viewport ranges
	// (xmin, ymin, xmax, ymax)
	double redViewport[4] = { 0.0, 0.0, 0.25, 1.0 };
	double greenViewport[4] = { 0.25, 0.0, 0.5, 1.0 };
	double blueViewport[4] = { 0.5, 0.0, 0.75, 1.0 };
	double combinedViewport[4] = { 0.75, 0.0, 1.0, 1.0 };
 
	// Setup renderers
	vtkSmartPointer<vtkRenderer> redRenderer =
		vtkSmartPointer<vtkRenderer>::New();
	redRenderer->SetViewport(redViewport);
	redRenderer->AddActor(redActor);
	redRenderer->ResetCamera();
	redRenderer->SetBackground(1.0, 1.0, 1.0);
 
	vtkSmartPointer<vtkRenderer> greenRenderer =
		vtkSmartPointer<vtkRenderer>::New();
	greenRenderer->SetViewport(greenViewport);
	greenRenderer->AddActor(greenActor);
	greenRenderer->ResetCamera();
	greenRenderer->SetBackground(1.0, 1.0, 1.0);
 
	vtkSmartPointer<vtkRenderer> blueRenderer =
		vtkSmartPointer<vtkRenderer>::New();
	blueRenderer->SetViewport(blueViewport);
	blueRenderer->AddActor(blueActor);
	blueRenderer->ResetCamera();
	blueRenderer->SetBackground(1.0, 1.0, 1.0);
 
	vtkSmartPointer<vtkRenderer> combinedRenderer =
		vtkSmartPointer<vtkRenderer>::New();
	combinedRenderer->SetViewport(combinedViewport);
	combinedRenderer->AddActor(combinedActor);
	combinedRenderer->ResetCamera();
	combinedRenderer->SetBackground(1.0, 1.0, 1.0);
 
	vtkSmartPointer<vtkRenderWindow> renderWindow =
		vtkSmartPointer<vtkRenderWindow>::New();
	renderWindow->AddRenderer(redRenderer);
	renderWindow->AddRenderer(greenRenderer);
	renderWindow->AddRenderer(blueRenderer);
	renderWindow->AddRenderer(combinedRenderer);
	renderWindow->SetSize(1200, 300);
	renderWindow->Render();
	renderWindow->SetWindowName("ImageAppendComponentsExample");
 
	vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
		vtkSmartPointer<vtkRenderWindowInteractor>::New();
	vtkSmartPointer<vtkInteractorStyleImage> style =
		vtkSmartPointer<vtkInteractorStyleImage>::New();
 
	renderWindowInteractor->SetInteractorStyle(style);
	renderWindowInteractor->SetRenderWindow(renderWindow);
	renderWindowInteractor->Initialize();
	renderWindowInteractor->Start();
 
	return 0;
}