OpenCV 90°旋转

顺时针旋转90°思路

| 1 | 2 |
---------
| 3 | 4 |

| 1 | 2 |     T        | 1 | 3 |     Y轴镜像    | 3 | 1 |
---------   ------->   ---------   ------->    ---------
| 3 | 4 |              | 2 | 4 |               | 4 | 2 |

逆时针旋转90°思路

| 1 | 2 |     T        | 1 | 3 |     X轴镜像    | 2 | 4 |
---------   ------->   ---------    ------->   ---------
| 3 | 4 |              | 2 | 4 |               | 1 | 3 |

OpenCV代码

#include <iostream>
#include <string>
#include <vector>

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>

using namespace std;
using namespace cv;

void myRotateClockWise90(Mat &src)
{
if (src.empty())
{
return;
}
// 矩阵转置
transpose(src, src);
//0: 沿X轴翻转； >0: 沿Y轴翻转； <0: 沿X轴和Y轴翻转
flip(src, src, 1);
}

void myRotateAntiClockWise90(Mat &src)
{
if (src.empty())
{
return;
}
transpose(src, src);
flip(src, src, 0);
}

int main(int argc, char* argv[])
{
const string imgpath = "D:/opencv.jpg";
Mat src = imread(imgpath, 1);
Mat srcT;
transpose(src, srcT);
imwrite("D:/opencvT.jpg", srcT);

Mat srcClockWise90 = src.clone();
myRotateClockWise90(srcClockWise90);
imwrite("D:/opencvCW90.jpg", srcClockWise90);

Mat srcAntiClockWise90 = src.clone();
myRotateAntiClockWise90(srcAntiClockWise90);
imwrite("D:/opencvACW90.jpg", srcAntiClockWise90);
return 0;
}

测试结果

参考