python中的opencv如何获取轮廓下顶点的坐标

您可以使用OpenCV的findContours函数来获取图像中的轮廓。在该函数的参数中，您需要指定要查找轮廓的图像以及要使用的轮廓查找模式。在找到轮廓后，您可以使用approxPolyDP函数来近似多边形，然后使用approxPolyDP函数返回的多边形边缘点数组来获取多边形的边缘点坐标。您还可以使用minAreaRect函数来获取多边形的外包矩形，然后使用boxPoints函数来获取矩形顶点的坐标。以下是一个获取轮廓顶点坐标的示例代码：

import cv2

# Load image and convert to grayscale
img = cv2.imread('image.jpg')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

# Find contours in the image
contours, hierarchy = cv2.findContours(gray, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)

# Iterate through each contour
for contour in contours:
    # Approximate contour with a polygon
    epsilon = 0.01 * cv2.arcLength(contour, True)
    approx = cv2.approxPolyDP(contour, epsilon, True)
    
    # Draw polygon on original image
    cv2.drawContours(img, [approx], 0, (0, 255, 0), 3)
    
    # Get coordinates of polygon vertices
    vertices = approx.ravel().reshape(-1, 2)
    
    # Print coordinates of vertices
    for vertex in vertices:
        print(vertex)
    
    # Fit a bounding box to the polygon
    rect = cv2.minAreaRect(approx)
    box = cv2.boxPoints(rect)
    
    # Draw bounding box on original image
    cv2.drawContours(img, [box.astype(int)], 0, (0, 0, 255), 2)

# Display the original image with contours and bounding boxes
cv2.imshow('Image', img)
cv2.waitKey(0)
cv2.destroyAllWindows()