基于OpenCV的数据可视化

Posted 2020-10-24 凤凰_1

在Opencv中有个Viz模块，可以显示三维物体，还可以实现三维动画，本来是很好的东东，但是里面的函数、类的说明太过简单，始终不得要领。不过其中一个扩展功能非常好，就是你可以在vtk中设计自己的模型类，在Opencv中的Viz3d窗口中显示。

在Matla中有个plot3d()函数，可以三维显示二维图像，可是在Opencv中却无法实现。因此，在这里我用vtk中的vtkSurfaceReconstructionFilter类，这是一个对空间点拟合曲面的函数，重新封装了该函数，创建了自己的类：MySurfaceReconstruction，该类可以直接在Viz中的Viz3d窗口中显示。

下面是该类的代码：

class MySurfaceReconstruction:public viz::Widget3D
{
public:
    MySurfaceReconstruction(const Mat&src, const viz::Color color = viz::Color::white());

};
MySurfaceReconstruction::MySurfaceReconstruction(const Mat &src, const viz::Color color)
{

    vtkSmartPointer<vtkPoints>m_Points=vtkSmartPointer<vtkPoints>::New();
    vtkSmartPointer<vtkCellArray>vertices=vtkSmartPointer<vtkCellArray>::New();
    int numOfpixs=0;
    for(int i=0;i<src.rows;i++)
    {
        for(int j=0;j<src.cols;j++)
        {
            double x=j,y=i;
            double z=src.at<double>(i,j);
            m_Points->InsertPoint(numOfpixs,x,y,z);  //_加入点信息
            vertices->InsertNextCell(numOfpixs);     //_加入细胞顶点信息----用于渲染点集
            vertices->InsertCellPoint(numOfpixs);
            numOfpixs ++;
        }
    }

    vtkSmartPointer<vtkPolyData>points=vtkSmartPointer<vtkPolyData>::New();
    points->SetPoints(m_Points);
    vtkSmartPointer<vtkSurfaceReconstructionFilter>surf=vtkSmartPointer<vtkSurfaceReconstructionFilter>::New();
    surf->SetInputData(points);

    vtkSmartPointer<vtkContourFilter>contour=vtkSmartPointer<vtkContourFilter>::New();
    contour->SetInputConnection(surf->GetOutputPort());
    contour->SetValue(0,0.0);

    vtkSmartPointer<vtkPolyDataMapper>pointMapper=vtkSmartPointer<vtkPolyDataMapper>::New();
    pointMapper->SetInputConnection(contour->GetOutputPort());
    vtkSmartPointer<vtkActor>actor=vtkSmartPointer<vtkActor>::New();
    actor->SetMapper(pointMapper);
    // Store this actor in the widget in order that visualizer can access it
    viz::WidgetAccessor::setProp(*this, actor);
    // Set the color of the widget. This has to be called after WidgetAccessor.
    setColor(color);

}

 

int main()
{
    /// Create a window
    viz::Viz3d myWindow("Creating Widgets");
    /// Create a triangle widget
    cv::Mat mat=Gaussian_kernel(15,1);
    mat *=10;
    MySurfaceReconstruction tw(mat, viz::Color::red());
    /// Show widget in the visualizer window
    myWindow.showWidget("my surface", tw);
    /// Start event loop
    myWindow.spin();
   return 0;
}