OpenCV - 校准鱼眼镜头误差（病态矩阵）

我正在尝试按照这些说明校准鱼眼镜头https://medium.com/@kenneth Jiang/calibrate-fisheye-lens-using-opencv-333b05afa0b0 https://medium.com/@kennethjiang/calibrate-fisheye-lens-using-opencv-333b05afa0b0您可以在其中找到我用于校准部分的完整代码。

我到达这一点：

N_OK = len(objpoints)
K = np.zeros((3, 3))
D = np.zeros((4, 1))
rvecs = [np.zeros((1, 1, 3), dtype=np.float64) for i in range(N_OK)]
tvecs = [np.zeros((1, 1, 3), dtype=np.float64) for i in range(N_OK)]  
rms, _, _, _, _ = \
    cv2.fisheye.calibrate(
        objpoints,
        imgpoints,
        gray.shape[::-1],
        K,
        D,
        rvecs,
        tvecs,
        calibration_flags,
        (cv2.TERM_CRITERIA_EPS+cv2.TERM_CRITERIA_MAX_ITER, 30, 1e-3)
    )
print("Found " + str(N_OK) + " valid images for calibration")
print("DIM=" + str(_img_shape[::-1]))
print("K=np.array(" + str(K.tolist()) + ")")
print("D=np.array(" + str(D.tolist()) + ")")

我收到此错误：

Traceback (most recent call last)
<ipython-input-10-deaca9981fe4> in <module>()
     13         tvecs,
     14         calibration_flags,
---> 15         (cv2.TERM_CRITERIA_EPS+cv2.TERM_CRITERIA_MAX_ITER, 30, 1e-3)
     16     )
     17 print("Found " + str(N_OK) + " valid images for calibration")

error: C:\ci\opencv_1512688052760\work\modules\calib3d\src\fisheye.cpp:1414: 
error: (-3) CALIB_CHECK_COND - Ill-conditioned matrix for input array 0 in 
function cv::internal::CalibrateExtrinsics

我不明白发生了什么事，我只能在互联网上找到很少的信息，有没有人经历过类似的事情并知道如何解决这个问题？

Thanks

这些是我正在使用的棋盘图像：

• https://i.stack.imgur.com/goHIg.jpg https://i.stack.imgur.com/goHIg.jpg
• https://i.stack.imgur.com/kja3O.jpg https://i.stack.imgur.com/kja3O.jpg
• https://i.stack.imgur.com/XbIzh.jpg https://i.stack.imgur.com/XbIzh.jpg
• https://i.stack.imgur.com/uQ9Gr.jpg https://i.stack.imgur.com/uQ9Gr.jpg
• https://i.stack.imgur.com/N8aLJ.jpg https://i.stack.imgur.com/N8aLJ.jpg
• https://i.stack.imgur.com/JMmmZ.jpg https://i.stack.imgur.com/JMmmZ.jpg
• https://i.stack.imgur.com/QJ8wn.jpg https://i.stack.imgur.com/QJ8wn.jpg
• https://i.stack.imgur.com/NmiFQ.jpg https://i.stack.imgur.com/NmiFQ.jpg
• https://i.stack.imgur.com/sQHdd.jpg https://i.stack.imgur.com/sQHdd.jpg
• https://i.stack.imgur.com/DNBuD.jpg https://i.stack.imgur.com/DNBuD.jpg
• https://i.stack.imgur.com/vFtOo.jpg https://i.stack.imgur.com/vFtOo.jpg
• https://i.stack.imgur.com/lhkF5.jpg https://i.stack.imgur.com/lhkF5.jpg

我认为这是因为你的变量calibration_flags设置了CALIB_CHECK_COND。 尝试禁用此标志。没有它，我就能够消除图像的扭曲（请参阅下面的链接）。

我不确定这张支票的用途是什么（文档 https://docs.opencv.org/3.4.1/db/d58/group__calib3d__fisheye.html不是很明确）。即使棋盘可见并被检测到，此标志也会拒绝我的 gopro Hero 3 的某些图像。就我而言，20 张图像中的一张未通过此测试。该图像的棋盘靠近左边框。

• https://i.stack.imgur.com/m2WF6.jpg https://i.stack.imgur.com/m2WF6.jpg
• https://i.stack.imgur.com/KiTRz.jpg https://i.stack.imgur.com/KiTRz.jpg
• https://i.stack.imgur.com/MhHyN.jpg https://i.stack.imgur.com/MhHyN.jpg
• https://i.stack.imgur.com/pSiyG.jpg https://i.stack.imgur.com/pSiyG.jpg
• https://i.stack.imgur.com/drXSL.jpg https://i.stack.imgur.com/drXSL.jpg
• https://i.stack.imgur.com/DDze1.jpg https://i.stack.imgur.com/DDze1.jpg
• https://i.stack.imgur.com/b6l8f.jpg https://i.stack.imgur.com/b6l8f.jpg
• https://i.stack.imgur.com/9MrAk.jpg https://i.stack.imgur.com/9MrAk.jpg
• https://i.stack.imgur.com/WYmg5.jpg https://i.stack.imgur.com/WYmg5.jpg
• https://i.stack.imgur.com/rmJ5Q.jpg https://i.stack.imgur.com/rmJ5Q.jpg
• https://i.stack.imgur.com/K8k8Y.jpg https://i.stack.imgur.com/K8k8Y.jpg
• https://i.stack.imgur.com/MiBER.jpg https://i.stack.imgur.com/MiBER.jpg

¹ 在 OpenCV 版本 >= 3.4.1 中错误信息 https://github.com/opencv/opencv/commit/5ca7dcc6e74b9c6068b8de1f49f289d6bc6b5a0b告诉您哪个图像未通过测试