opencv-warpAffine仿射变换_ios


仿射变换对应着五种变换:平移，缩放，旋转，翻转，错切

opencv-warpAffine仿射变换_ios_02



opencv-warpAffine仿射变换_仿射变换_03



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


int main(int argc, char** argv) {

    cv::Mat I = cv::imread("D:/bb/tu/ma.png");
    cv::Mat dst;

    //设置原图3个变换顶点
    cv::Point2f AffinePoints0[3] = { cv::Point2f(10, 10), cv::Point2f(10, 300), cv::Point2f(300, 10) };
    //仿射变换是根据三个点来变换的

    //设置目标图像3个变换顶点
    cv::Point2f AffinePoints1[3] = { cv::Point2f(50, 50), cv::Point2f(50, 350), cv::Point2f(250, 10) };

    cv::Mat Trans = getAffineTransform(AffinePoints0, AffinePoints1);//计算变换矩阵
    //参数1:原图像的3个点
    //参数2:目标图像的3个点

    warpAffine(I, dst, Trans, cv::Size(I.cols, I.rows));//矩阵仿射变换
    //参数1:变换前图像
    //参数2:变换后图像
    //参数3:变换矩阵，用另一个函数getAffineTransform()计算
    //参数4:输出图像大小
    //参数5:参数int flags=INTER_LINEAR：设置插值方式，默认方式为线性插值,看下图

    imshow("src", I);
    imshow("dst", dst);

    cv::waitKey(0);
    return 0;
}


opencv-warpAffine仿射变换_仿射变换_04



opencv-warpAffine仿射变换_ios_05


getRotationMatrix2D旋转

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


int main(int argc, char** argv) {

    cv::Mat src = cv::imread("D:/bb/tu/1.jpg");
    cv::imshow("src", src);
    int rows = src.rows;
    int cols = src.cols;
    cv::Point2f center = cv::Point2f(rows / 2, cols / 2);

    cv::Mat Trans,dst;
    double angle = 90.0;
    double scale = 0.8;
    Trans =getRotationMatrix2D(center, angle, scale);//计算变换矩阵--旋转
    //参数1:旋转的中心点
    //参数2:旋转角度，正号为逆时针，负号为顺时针
    //参数3:旋转后图像相比原来的缩放比例，1为等比例缩放

    warpAffine(src, dst, Trans, cv::Size(src.cols, src.rows));//矩阵仿射变换
    cv::imshow("dst", dst);
    cv::waitKey(0);
    return 0;
}

opencv-warpAffine仿射变换_ios_06