python凹多边形分割_使用Opencv python从图像裁剪凹面多边形

您可以通过3个步骤进行操作：

1)在图像上创建遮罩

mask = np.zeros((height, width))

points = np.array([[[10,150],[150,100],[300,150],[350,100],[310,20],[35,10]]])

cv2.fillPoly(mask, points, (255))

2)将蒙版应用于原始图像

res = cv2.bitwise_and(img,img,mask = mask)

3)(可选)您可以删除裁剪图像以缩小图像

rect = cv2.boundingRect(points) # returns (x,y,w,h) of the rect

cropped = res[rect[1]: rect[1] + rect[3], rect[0]: rect[0] + rect[2]]

有了这个，您应该在图像末尾裁剪

更新

为了完整起见，下面是完整的代码：

import numpy as np

import cv2

img = cv2.imread("test.png")

height = img.shape[0]

width = img.shape[1]

mask = np.zeros((height, width), dtype=np.uint8)

points = np.array([[[10,150],[150,100],[300,150],[350,100],[310,20],[35,10]]])

cv2.fillPoly(mask, points, (255))

res = cv2.bitwise_and(img,img,mask = mask)

rect = cv2.boundingRect(points) # returns (x,y,w,h) of the rect

cropped = res[rect[1]: rect[1] + rect[3], rect[0]: rect[0] + rect[2]]

cv2.imshow("cropped" , cropped )

cv2.imshow("same size" , res)

cv2.waitKey(0)