VTK_Learning_图像基本操作_彩色图像生成灰度图像_彩色图像成分提取

1.灰度图像映射

vtkImageLuminance负责将一个RGB彩色图像转换为一个单组分的灰度图像。映射公式如下：
luminance = 0.3*R + 0.59*G + 0.11*B
该公式中，R为输入图像的第一分量（红色），G为第二分量（绿色），B为第三分量（蓝色）。这个计算结果计算一个RGB颜色的亮度。该类的使用也比较简单，用户无须设置参数，代码如下：
 

#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL);
 
#include <vtkSmartPointer.h>
#include <vtkBMPReader.h>
#include <vtkImageLuminance.h>
#include <vtkImageActor.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleImage.h>
 
int main()
{
  vtkSmartPointer<vtkBMPReader> reader =
    vtkSmartPointer<vtkBMPReader>::New();
  reader->SetFileName("lena.bmp");
 
  vtkSmartPointer<vtkImageLuminance> luminanceFilter =
    vtkSmartPointer<vtkImageLuminance>::New();
  luminanceFilter->SetInputConnection(reader->GetOutputPort());
  luminanceFilter->Update();
  //原始演员
  vtkSmartPointer<vtkImageActor> origActor =
    vtkSmartPointer<vtkImageActor>::New();
  origActor->SetInputData(reader->GetOutput());
  //灰度演员
  vtkSmartPointer<vtkImageActor> shiftscaleActor =
    vtkSmartPointer<vtkImageActor>::New();
  shiftscaleActor->SetInputData(luminanceFilter->GetOutput());
  double origView[4] = { 0.0, 0.0, 0.5, 1.0 };
  double shiftscaleView[4] = { 0.5, 0.0, 1.0, 1.0 };
  //原始演员化妆
  vtkSmartPointer<vtkRenderer> origRender =
    vtkSmartPointer<vtkRenderer>::New();
  origRender->SetViewport(origView);
  origRender->AddActor(origActor);
  origRender->ResetCamera();
  origRender->SetBackground(1.0, 1.0, 1.0);
  //灰度演员化妆
  vtkSmartPointer<vtkRenderer> shiftscaleRender =
    vtkSmartPointer<vtkRenderer>::New();
  shiftscaleRender->SetViewport(shiftscaleView);
  shiftscaleRender->AddActor(shiftscaleActor);
  shiftscaleRender->ResetCamera();
  shiftscaleRender->SetBackground(1.0, 1.0, 1.0);
 
  vtkSmartPointer<vtkRenderWindow> renderwindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderwindow->AddRenderer(origRender);
  renderwindow->AddRenderer(shiftscaleRender);
  renderwindow->SetSize(720, 480);
  renderwindow->Render();
  renderwindow->SetWindowName("RGB to Gray");
 
  vtkSmartPointer<vtkRenderWindowInteractor> rwi =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  vtkSmartPointer<vtkInteractorStyleImage> style =
    vtkSmartPointer<vtkInteractorStyleImage>::New();
  rwi->SetInteractorStyle(style);
  rwi->SetRenderWindow(renderwindow);
  rwi->Initialize();
 
  rwi->Start();
  return 0;
}

2.彩色图像RGB成分提取

VTK中利用vtkImageExtractComponents可以方便的提取出彩色图像的各个颜色分量，该类的使用比较简单，只需要设置要提取的分量序号即可。下面代码说明了怎样提取彩色图像的某个颜色分量。

#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL);
 
#include <vtkSmartPointer.h>
#include <vtkBMPReader.h>
#include <vtkImageExtractComponents.h>
#include <vtkImageActor.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleImage.h>
 
int main()
{
  vtkSmartPointer<vtkBMPReader> reader =
    vtkSmartPointer<vtkBMPReader>::New();
  reader->SetFileName("lena.bmp");
 
  vtkSmartPointer<vtkImageExtractComponents> redComponent =
    vtkSmartPointer<vtkImageExtractComponents>::New();
  redComponent->SetInputConnection(reader->GetOutputPort());
  redComponent->SetComponents(0);
  redComponent->Update();
 
  vtkSmartPointer<vtkImageExtractComponents> greenComponent =
    vtkSmartPointer<vtkImageExtractComponents>::New();
  greenComponent->SetInputConnection(reader->GetOutputPort());
  greenComponent->SetComponents(1);
  greenComponent->Update();
 
  vtkSmartPointer<vtkImageExtractComponents> blueComponent =
    vtkSmartPointer<vtkImageExtractComponents>::New();
  blueComponent->SetInputConnection(reader->GetOutputPort());
  blueComponent->SetComponents(2);
  blueComponent->Update();
  //创建演员
  vtkSmartPointer<vtkImageActor> origActor =
    vtkSmartPointer<vtkImageActor>::New();
  origActor->SetInputData(reader->GetOutput());
 
  vtkSmartPointer<vtkImageActor> redActor =
    vtkSmartPointer<vtkImageActor>::New();
  redActor->SetInputData(redComponent->GetOutput());
 
  vtkSmartPointer<vtkImageActor> greenActor =
    vtkSmartPointer<vtkImageActor>::New();
  greenActor->SetInputData(greenComponent->GetOutput());
 
  vtkSmartPointer<vtkImageActor> blueActor =
    vtkSmartPointer<vtkImageActor>::New();
  blueActor->SetInputData(blueComponent->GetOutput());
  //定义窗口 并化妆
  double origView[4] = { 0.0, 0.0, 0.25, 1.0 };
  double redView[4] = { 0.25, 0.0, 0.5, 1.0 };
  double greenView[4] = { 0.5, 0.0, 0.75, 1.0 };
  double blueView[4] = { 0.75, 0.0, 1.0, 1.0 };
 
  vtkSmartPointer<vtkRenderer> origRender =
    vtkSmartPointer<vtkRenderer>::New();
  origRender->SetViewport(origView);
  origRender->AddActor(origActor);
  origRender->ResetCamera();
  origRender->SetBackground(1.0, 1.0, 1.0);
 
  vtkSmartPointer<vtkRenderer> redRender =
    vtkSmartPointer<vtkRenderer>::New();
  redRender->SetViewport(redView);
  redRender->AddActor(redActor);
  redRender->ResetCamera();
  redRender->SetBackground(1.0, 1.0, 1.0);
 
  vtkSmartPointer<vtkRenderer> greenRender =
    vtkSmartPointer<vtkRenderer>::New();
  greenRender->SetViewport(greenView);
  greenRender->AddActor(greenActor);
  greenRender->ResetCamera();
  greenRender->SetBackground(1.0, 1.0, 1.0);
 
  vtkSmartPointer<vtkRenderer> blueRender =
    vtkSmartPointer<vtkRenderer>::New();
  blueRender->SetViewport(blueView);
  blueRender->AddActor(blueActor);
  blueRender->ResetCamera();
  blueRender->SetBackground(1.0, 1.0, 1.0);
  //上舞台
  vtkSmartPointer<vtkRenderWindow> renderwindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderwindow->AddRenderer(origRender);
  renderwindow->AddRenderer(redRender);
  renderwindow->AddRenderer(greenRender);
  renderwindow->AddRenderer(blueRender);
  renderwindow->SetSize(960, 320);
  renderwindow->Render();
  renderwindow->SetWindowName("ExtraImageColorComponents");
  //设置交互
  vtkSmartPointer<vtkRenderWindowInteractor> rwi =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  vtkSmartPointer<vtkInteractorStyleImage> style =
    vtkSmartPointer<vtkInteractorStyleImage>::New();
  rwi->SetInteractorStyle(style);
  rwi->SetRenderWindow(renderwindow);
  rwi->Initialize();
 
  rwi->Start(); 
  return 0;
}