图像金字塔与图片尺寸缩放

一、图像金字塔

 

 二、尺寸调整:resize()函数

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

#include<opencv2/opencv.hpp>
#include<iostream>

using namespace cv;
using namespace std;

int main(int argc, char** argv) {
    Mat srcImage = imread("C:\Users\Nelsoner\Desktop\Camera Roll\05.jpg", 1);
    
    Mat tmpImage, dstImage1, dstImage2;
    tmpImage = srcImage;

    imshow("【原图】", srcImage);
    
    resize(tmpImage, dstImage1, Size(tmpImage.cols / 2, tmpImage.rows / 2), (0, 0), (0, 0), 3);
    resize(tmpImage, dstImage2, Size(tmpImage.cols * 2, tmpImage.rows * 2), (0, 0), (0, 0), 3);

    imshow("【效果图一】", dstImage1);
    imshow("【效果图二】", dstImage2);

    waitKey(0);

    return 0;
}

三、图像金字塔，向上采样pyrUp()函数

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

 

#include<opencv2/opencv.hpp>
#include<iostream>

using namespace cv;
using namespace std;

int main(int argc, char** argv) {
    Mat srcImage = imread("C:\Users\Nelsoner\Desktop\Camera Roll\05.jpg", 1);
    
    Mat tmpImage, dstImage;
    tmpImage = srcImage;

    imshow("【原图】", srcImage);
    pyrUp(tmpImage, dstImage, Size(tmpImage.cols * 2, tmpImage.rows * 2));
    imshow("【效果图】", dstImage);
    
    waitKey(0);
    return 0;
}

 四、图像金字塔，向下采样pyrDown()函数

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