opencv学习笔记8 高斯金字塔，拉普拉斯金字塔，调整大小

一。图像金字塔

高斯金字塔用来向下降采样图像

拉普拉斯金字塔用来从金字塔底层图像中向上采样重建一个图像

1.像上采样

void pyrUp(InputArray src, OutputArraydst, const Size& dstsize=Size(), int borderType=BORDER_DEFAULT )

2.向下采样

void pyrDown(InputArray src,OutputArray dst, const Size& dstsize=Size(), int borderType=BORDER_DEFAULT)

#include<opencv.hpp>
using namespace cv;
int main()
{
    Mat src = imread("F:/opencv/lena.jpg");
    Mat pyrup,pyrdown;
    pyrUp(src, pyrup, Size(src.cols * 2, src.rows * 2)); //图片放大
    pyrDown(src, pyrdown, Size(src.cols / 2, src.rows / 2)); //图片缩小
    imshow("src", src);
    imshow("pyrup", pyrup);
    imshow("pyrdown", pyrdown);
    waitKey();
    return 0;
}

二。调整图像大小

void resize(InputArray src,OutputArray dst, Size dsize, double fx=0, double fy=0, int interpolation=INTER_LINEAR )

#include<iostream>
#include<vector>
#include<opencv2/opencv.hpp>
using namespace std;
using namespace cv;
int main() 
{
    Mat src = imread("E:/test.jpg");
    Mat dst1, dst2 = Mat::zeros(1000, 1000,CV_8UC3);
    imshow("src", src);
    resize(src, dst1, Size(), 0.5, 0.5);
    imshow("dst1", dst1);
    resize(src, dst2, dst2.size());
    imshow("dst2", dst2);
    waitKey();
    return 0;
}