尺度空间理论

  看到一篇博文，主要讲的是图像金字塔：http://www.cnblogs.com/ronny/p/3886013.html

  最后博主关于尺度的选择很有启发性，当我们不知道物体的尺度有多大时，可以先定义一个模板，再与金字塔的每层图像进行匹配。

  

#include "opencv2/core/core.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/calib3d/calib3d.hpp"
#include "opencv2/nonfree/nonfree.hpp"
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/imgproc/imgproc.hpp>
#include <iostream>
using namespace cv;
using namespace std;


enum pyrType { PYR_GUASS, PYR_LAPLACE };
void genPyr(const Mat& imgSrc, vector<Mat>& outPutArray, int TYPE, int level)
{
    outPutArray.assign(level + 1, Mat());
    outPutArray[0] = imgSrc.clone(); // the 0 level is the image. 
    for (int i = 0; i != level; i++)
    {
        pyrDown(outPutArray[i], outPutArray[i + 1]);
    }
    if (PYR_GUASS == TYPE)
    {
        return;
    }
    for (int i = 0; i != level; i++)
    {
        Mat UpSampleImg;
        pyrUp(outPutArray[i + 1], UpSampleImg, outPutArray[i].size());
        outPutArray[i] -= UpSampleImg;
    }
}
vector<Mat> outPutArray;
Mat g_srcImage, g_dstImage, g_tmpImage;
int main()
{
    g_srcImage = imread("1.jpg");
    //namedWindow("原图", WINDOW_AUTOSIZE);
    //imshow("原图", g_srcImage);

    g_tmpImage = g_srcImage;
    g_dstImage = g_tmpImage;
    int key = 0;
    genPyr(g_srcImage, outPutArray, 1, 2);

    imshow("图", outPutArray[1]);
        /*key = 's';
        switch (key)
        {
        case 27:
            return 0;
            break;
        case 'a':
            //图像尺寸加倍，在每个维度上扩大为原来的两倍，新增的行（偶数行）以0填充，
            //然后给指定的滤波器卷积,去估计“丢失像素的近似值”
            pyrUp(g_tmpImage, g_dstImage, Size(g_tmpImage.cols*2 , g_tmpImage.rows*2 ));
            break;
        case 'w':
            resize(g_tmpImage, g_dstImage, Size(g_tmpImage.cols * 2, g_tmpImage.rows * 2));
            break;
        case 'd':
            //对图像进行高斯内核卷积，将所有偶数的行和列去除
            pyrDown(g_tmpImage, g_dstImage, Size(g_tmpImage.cols / 2, g_tmpImage.rows / 2));
            break;
        case 's':
            resize(g_tmpImage, g_dstImage, Size(g_tmpImage.cols /2, g_tmpImage.rows / 2));
        
        }
        imshow("目标图", g_dstImage);
    */

        waitKey(0);
        return 0;
}