请提供一个估算摄像机外参和内参的计算方法,并用C++和PYTHON代码实现
时间: 2024-03-01 21:55:30 浏览: 136
估算摄像机外参和内参的计算方法是使用相机标定。相机标定是通过拍摄已知物体的图像并测量其实际尺寸,来计算相机的内参和外参的过程。
具体步骤如下:
1. 准备标定板:使用黑白棋盘格或者其他已知形状的标定板,将其放置在拍摄场景中。
2. 拍摄标定板:使用相机拍摄标定板的多张图像,保证标定板在拍摄过程中位置和姿态不变。
3. 提取角点:对每张图像进行角点提取,即在标定板上检测黑白交界处的角点。
4. 计算内参:使用提取的角点计算相机的内参,包括相机的焦距、主点、畸变参数等。
5. 计算外参:使用提取的角点以及标定板的已知尺寸,通过三维重建的方法计算相机的外参,包括相机的旋转矩阵和平移向量。
下面给出C++和Python代码实现:
C++代码实现:
```c++
#include <iostream>
#include <vector>
#include <opencv2/opencv.hpp>
using namespace std;
using namespace cv;
int main()
{
// 1. 准备标定板
Size boardSize(9, 6); // 棋盘格大小
float squareSize = 20; // 格子大小,单位mm
vector<vector<Point3f>> objectPoints; // 保存标定板上每个格子的三维坐标
vector<vector<Point2f>> imagePoints; // 保存每张图像中提取到的角点坐标
vector<Point3f> obj; // 标定板上每个格子的三维坐标
for(int i = 0; i < boardSize.height; ++i)
{
for(int j = 0; j < boardSize.width; ++j)
{
obj.push_back(Point3f(j * squareSize, i * squareSize, 0));
}
}
// 2. 拍摄标定板
VideoCapture cap(0); // 打开相机
if(!cap.isOpened())
{
cout << "无法打开相机!" << endl;
return -1;
}
namedWindow("标定图像", WINDOW_NORMAL);
while(true)
{
Mat frame, gray;
cap >> frame; // 获取相机图像
cvtColor(frame, gray, COLOR_BGR2GRAY);
vector<Point2f> corners;
bool found = findChessboardCorners(gray, boardSize, corners, CALIB_CB_ADAPTIVE_THRESH | CALIB_CB_NORMALIZE_IMAGE);
if(found)
{
drawChessboardCorners(frame, boardSize, corners, found);
imshow("标定图像", frame);
char c = waitKey(1);
if(c == 27)
{
break;
}
if(c == ' ')
{
objectPoints.push_back(obj);
imagePoints.push_back(corners);
cout << "已拍摄 " << objectPoints.size() << " 张图像" << endl;
}
}
else
{
imshow("标定图像", frame);
waitKey(1);
}
}
destroyWindow("标定图像");
cout << "拍摄完成!" << endl;
// 3. 计算内参
Mat cameraMatrix, distCoeffs;
vector<Mat> rvecs, tvecs;
calibrateCamera(objectPoints, imagePoints, Size(gray.rows, gray.cols), cameraMatrix, distCoeffs, rvecs, tvecs);
cout << "相机内参:" << endl << cameraMatrix << endl;
cout << "畸变参数:" << endl << distCoeffs << endl;
// 4. 计算外参
Mat rvec, tvec;
bool found = solvePnP(obj, imagePoints[0], cameraMatrix, distCoeffs, rvec, tvec);
if(found)
{
cout << "相机旋转向量:" << endl << rvec << endl;
cout << "相机平移向量:" << endl << tvec << endl;
}
else
{
cout << "无法计算相机外参!" << endl;
}
return 0;
}
```
Python代码实现:
```python
import cv2
import numpy as np
# 准备标定板
board_size = (9, 6) # 棋盘格大小
square_size = 20 # 格子大小,单位mm
object_points = [] # 保存标定板上每个格子的三维坐标
obj = np.zeros((board_size[0] * board_size[1], 3), np.float32)
obj[:, :2] = np.mgrid[0:board_size[0], 0:board_size[1]].T.reshape(-1, 2) * square_size
for i in range(10):
object_points.append(obj)
# 拍摄标定板
cap = cv2.VideoCapture(0) # 打开相机
if not cap.isOpened():
print("无法打开相机!")
exit()
cv2.namedWindow("标定图像", cv2.WINDOW_NORMAL)
image_points = []
while True:
ret, frame = cap.read() # 获取相机图像
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
found, corners = cv2.findChessboardCorners(gray, board_size, cv2.CALIB_CB_ADAPTIVE_THRESH | cv2.CALIB_CB_NORMALIZE_IMAGE)
if found:
cv2.drawChessboardCorners(frame, board_size, corners, found)
cv2.imshow("标定图像", frame)
c = cv2.waitKey(1)
if c == 27:
break
if c == ord(' '):
image_points.append(corners)
print("已拍摄 {} 张图像".format(len(image_points)))
else:
cv2.imshow("标定图像", frame)
cv2.waitKey(1)
cv2.destroyWindow("标定图像")
print("拍摄完成!")
# 计算内参和外参
_, camera_matrix, dist_coeffs, rvecs, tvecs = cv2.calibrateCamera(object_points, image_points, gray.shape[::-1], None, None)
print("相机内参:")
print(camera_matrix)
print("畸变参数:")
print(dist_coeffs)
rvec, tvec, inliers = cv2.solvePnPRansac(obj, image_points[0], camera_matrix, dist_coeffs)
print("相机旋转向量:")
print(rvec)
print("相机平移向量:")
print(tvec)
```
以上是估算摄像机外参和内参的计算方法和代码实现。需要注意的是,拍摄标定板的过程中,需要保证标定板在拍摄过程中位置和姿态不变,否则会影响标定的结果。
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