openCV 图像绕中心旋转

#include "cv.h"                             //  OpenCV 文件头
#include "highgui.h"
#include "cvaux.h"
#include "cxcore.h"
#include "opencv2/opencv.hpp"
#include "opencv2/imgproc.hpp"
#include 
#include 
using namespace cv;
using namespace std;
Mat rotateImage1(Mat img, int degree)
{
	degree = -degree;
	double angle = degree  * CV_PI / 180.; // 弧度  
	double a = sin(angle), b = cos(angle);
	int width = img.cols;
	int height = img.rows;
	int width_rotate = int(height * fabs(a) + width * fabs(b));
	int height_rotate = int(width * fabs(a) + height * fabs(b));
	//旋转数组map
	// [ m0  m1  m2 ] ===>  [ A11  A12   b1 ]
	// [ m3  m4  m5 ] ===>  [ A21  A22   b2 ]
	float map[6];
	Mat map_matrix = Mat(2, 3, CV_32F, map);
	// 旋转中心
	CvPoint2D32f center = cvPoint2D32f(width / 2, height / 2);
	CvMat map_matrix2 = map_matrix;
	cv2DRotationMatrix(center, degree, 1.0, &map_matrix2);
	map[2] += (width_rotate - width) / 2;
	map[5] += (height_rotate - height) / 2;
	Mat img_rotate;
	//对图像做仿射变换
	//CV_WARP_FILL_OUTLIERS - 填充所有输出图像的象素。
	//如果部分象素落在输入图像的边界外，那么它们的值设定为 fillval.
	//CV_WARP_INVERSE_MAP - 指定 map_matrix 是输出图像到输入图像的反变换，
	warpAffine(img, img_rotate, map_matrix, Size(width_rotate, height_rotate), 1, 0, 0);
	return img_rotate;
}
int main(int argc, char *argv[])
{
	int degree;
	Mat m_SrcImg;
	m_SrcImg = imread("lena2.jpg");
	namedWindow("原图像", 1);
	imshow("原图像", m_SrcImg);
	cout << "请输入旋转的度数：";
	cin >> degree;
	Mat m_ResImg = rotateImage1(m_SrcImg, degree);
	namedWindow("旋转后图像", 1);
	imshow("旋转后图像", m_ResImg);
	waitKey(0);
}