Question

我正在图像处理中开发一个应用程序，我想将视口坐标映射到世界窗口坐标（我正在使用python），并在opencv cpp文档中获得了变换旋转矩阵和失真系数，据写照相机可校准可以用于此目的，但我找不到任何人可以提供帮助吗？

Answer 1

要进行相机校准，您必须首先从以下链接打印国际象棋纸：chess for print 然后使用以下代码进行校准：

1）将象棋纸放在照相机前面的不同位置，此代码打开照相机并检测象棋纸。多次检测棋盘后，将计算出系数矩阵，以使摄像机图像保持不失真。

import numpy as np
import cv2

objp = np.zeros((6 * 7, 3), np.float32)
objp[ : , : 2] = np.mgrid[0 : 7, 0 : 6].T.reshape(-1, 2)
objpoints = []
imgpoints = []

criteria = (cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_MAX_ITER, 30, 0.001)

cam = cv2.VideoCapture(0)
(w, h) = (int(cam.get(4)), int(cam.get(3)))

while(True):
    _ , frame = cam.read()
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    ret, corners = cv2.findChessboardCorners(gray, (7, 6), None)

    if ret == True:
        objpoints.append(objp)
        corners = cv2.cornerSubPix(gray, corners, (11, 11), (-1, -1), criteria)
        imgpoints.append(corners)

        cv2.drawChessboardCorners(frame, (7, 6), corners, ret)
        cv2.imshow('Find Chessboard', frame)
        cv2.waitKey(0)
    cv2.imshow('Find Chessboard', frame)
    print "Number of chess boards find:", len(imgpoints)        
    if cv2.waitKey(1) == 27:
        break

ret, oldMtx, coef, rvecs, tvecs = cv2.calibrateCamera(objpoints, imgpoints,
                                                      gray.shape[: : -1], None, None)
newMtx, roi = cv2.getOptimalNewCameraMatrix(oldMtx, coef, (w, h), 1, (w, h))

print "Original Camera Matrix:\n", oldMtx
print "Optimal Camera Matrix:\n", newMtx

np.save("Original camera matrix", oldMtx)
np.save("Distortion coefficients", coef)
np.save("Optimal camera matrix", newMtx)

cam.release()
cv2.destroyAllWindows()

2）然后使用以下示例代码加载矩阵并应用undistort函数校正摄像机图像：

import numpy as np
import cv2

oldMtx = np.load("Original camera matrix.npy")
coef = np.load("Distortion coefficients.npy")
newMtx = np.load("Optimal camera matrix.npy")

cam = cv2.VideoCapture(0)
(w, h) = (int(cam.get(4)), int(cam.get(3)))

while(True):
    _ , frame = cam.read()

    undis = cv2.undistort(frame, oldMtx, coef, newMtx)

    cv2.imshow("Original vs Undistortion", np.hstack([frame, undis]))
    key = cv2.waitKey(1)
    if key == 27:
        break
cam.release()
cv2.destroyAllWindows()

这些代码对我有用。祝你好运

OpenCV摄像机校准用于世界查看端口映射

1 个答案: