基于OpenCV的三维数据点的曲面重构_MySurefaceReconstruction

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。

本程序中所需要的头文件如下：

#ifndef INITIAL_OPENGL
#define INITIAL_OPENGL
#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL)
VTK_MODULE_INIT(vtkInteractionStyle)
#endif

#include <iostream>
#include <opencv2/opencv.hpp>
#include <opencv2/viz/vizcore.hpp>
#include <opencv2/viz/viz3d.hpp>
#include <opencv2/viz/widget_accessor.hpp>
using namespace cv;
using namespace std;

#include "vtkPolyDataMapper.h"
#include "vtkActor.h"
#include "vtkSmartPointer.h"
#include "vtkProperty.h"
#include "vtkPoints.h"
#include "vtkCellArray.h"
#include "vtkSurfaceReconstructionFilter.h"
#include "vtkContourFilter.h"

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);

}

为了方便测试，自定义了一个高斯分布函数：

//*9. 获取二维高斯卷积核
Mat Gaussian_kernel(int kernel_size, double sigma)
{
    int c = (kernel_size) / 2;
    Mat kernel(kernel_size, kernel_size, CV_64FC1);
    double s = 2 * sigma*sigma;
    for (int i = 0; i < kernel_size; i++)
    {
        for (int j = 0; j < kernel_size; j++)
        {
            double x = j - c;
            double y=i - c;
            kernel.ptr<double>(i)[j] = exp(-(x*x+y*y)/s) ;
        }
    }
    Scalar sumOfKernel= cv::sum(kernel);//求kernel的所有像素值之和
    kernel /=sumOfKernel[0];//归一化，避免卷积过程中增大总能量
    return kernel;
}

 下面是测试程序，通过上面的高斯函数创建一个高斯分布二维矩阵mat，作为MySurfaceReconstruction类的初始输入，MySurfaceReconstruction可以将mat转化成Widget3d类物体，并通过Viz3d显示。

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;
}

 下面是运行结果：