python 中给定点集的凸包？

Question

我正在尝试寻找凸包以便使用 opencv 库，代码是：

import cv2
import numpy as np
a = [[0, 0], [1, 0], [0, 1], [1, 1], [0.5, 0.5]]
cv2.convexHull(np.array(a))

我收到一个错误，它是 -

Traceback (most recent call last):
  File "<pyshell#10>", line 1, in <module>
    cv2.convexHull(np.array(a))
error: C:\projects\opencv-python\opencv\modules\imgproc\src\convhull.cpp:137: error: (-215) total >= 0 && (depth == 5 || depth == 4) in function cv::convexHull

如何解决？

Answer 1

关键是 C++ 代码需要一个 "two-channel or three-channel floating-point array, where each element is a 2D/3D vector"，它在 Python/NumPy 中转换为一个 3 维数组。

import cv2
import numpy as np
a = [[0, 0], [1, 0], [0, 1], [1, 1], [0.5, 0.5]]
cv2.convexHull(np.array(a,dtype='float32'))

来源：- http://answers.opencv.org/question/252/cv2perspectivetransform-with-python/

python 中给定点集的凸包？

Convex hull in python for given set of points?

python

opencv

convex-hull