图像任意旋转

 1 #include <iostream>
 2 #include<opencv2/opencv.hpp>
 3 #include <deque>
 4 using namespace std;
 5 using namespace cv;
 6 void Rotate_vertical(Mat &src, Mat &dst, float angle)//src原图像，dst输出图像，旋转角度
 7 {
 8     float rad = (float)(angle / 180.0 * CV_PI);
 9 
10     //填充图像
11     int maxBorder = (int)(max(src.cols, src.rows)* 1.414); //即为sqrt(2)*max
12     int dx = (maxBorder - src.cols) / 2;
13     int dy = (maxBorder - src.rows) / 2;
14     copyMakeBorder(src, dst, dy, dy, dx, dx, BORDER_CONSTANT);
15 
16     //旋转
17     Point2f center((float)(dst.cols / 2), (float)(dst.rows / 2));
18     Mat affine_matrix = getRotationMatrix2D(center, angle, 1.0);//求得旋转矩阵
19     warpAffine(dst, dst, affine_matrix, dst.size());
20 
21     //计算图像旋转之后包含图像的最大的矩形
22     float sinVal = abs(sin(rad));
23     float cosVal = abs(cos(rad));
24     Size targetSize((int)(src.cols * cosVal + src.rows * sinVal),
25         (int)(src.cols * sinVal + src.rows * cosVal));
26 
27     //剪掉多余边框
28     int x = (dst.cols - targetSize.width) / 2;
29     int y = (dst.rows - targetSize.height) / 2;
30     Rect rect(x, y, targetSize.width, targetSize.height);
31     dst = Mat(dst, rect);
32 }
33 int main()
34 {
35     Mat img = imread("1", 0);
36     Mat img_rotate;
37     float angle = 78.7;
38     Rotate_vertical(img, img_rotate, angle);
39     imshow("旋转后的图像", img_rotate);
40     waitKey(0);
41 }