【无标题】图片旋转代码，c++不调库

#include 
#include
#define PI 3.14159265
using namespace std;
using namespace cv;
// TODO: 在此添加命令处理程序代码
	String imagename = "D:\image\1.jpg";//自己的图片路径

	Mat img1 = imread(imagename, 1);
	double jiaodu = -PI / 6;//旋转角度是以π为准的
	resize(img1, img1, Size(600, 300));//重新设置图片大小，不设置也可以
	
	imshow("原图", img1);
	int cPointB, cPointG, cPointR, x1, y1, centerx, centery, midx, midy;
	Mat img2(img1.rows*2, img1.cols*2, CV_8UC3, cv::Scalar(3));//重新定义一个大一点的图片来放置
                                                                                                        //变换后的图片
	
	
	centery = int(img1.rows / 2), centerx = int(img1.cols / 2);//找到旋转中心
	midx = cos(jiaodu)*centerx - sin(jiaodu)*centery - centerx;//找到旋转中心 的偏移量
	midy = cos(jiaodu)*centery + sin(jiaodu)*centerx - centery;
	for (int i = 0; i < img2.rows; i++)
	{
		for (int j = 0; j < img2.cols; j++)
		{//从最后目标图片开始，反向映射回去，因为旋转的时候会造成坐标溢出，则将坐标向下平移，
//达到旋转之后还能够有原图的
			x1 = int(cos(jiaodu)*(j- img1.cols/2) - sin(jiaodu)*(i - img1.rows / 2) - midx );
			y1 = int(cos(jiaodu)*(i- img1.rows / 2) + sin(jiaodu)*(j - img1.cols / 2) - midy);
//判断如果反映射回去超过原图区域，则没有像素值，直接省去
			if (x1 < 0 || x1 >= img1.cols || y1 < 0 || y1 >= img1.rows)
			{
				img2.at(i, j)[0] = 0;
				img2.at(i, j)[0] = 0;
				img2.at(i, j)[0] = 0;
				continue;
			}
			//cout << x1 << " " << y1 << ",";
			img2.at(i, j)[0] = img1.at(y1, x1)[0];
			img2.at(i, j)[1] = img1.at(y1, x1)[1];
			img2.at(i, j)[2] = img1.at(y1, x1)[2];


		}

	}
	imshow("30度旋转", img2);