写一个找到图片中物体轮廓的曲率突变的点坐标的python程序,调用opencv
时间: 2024-09-13 08:11:40 浏览: 14
在Python中,使用OpenCV库可以方便地处理图像并找出物体轮廓的曲率突变点。下面是一个简单的示例,展示了如何使用`cv2.findContours`函数获取轮廓,并通过霍夫圆检测算法计算曲线的弧度变化,从而定位到突变点:
```python
import cv2
import numpy as np
def find_contour_curve_points(image_path):
# 读取图像
image = cv2.imread(image_path, cv2.IMREAD_GRAYSCALE)
# 高斯模糊有助于边缘检测
blurred_image = cv2.GaussianBlur(image, (5, 5), 0)
# 转换为二值图像
_, thresholded = cv2.threshold(blurred_image, 127, 255, cv2.THRESH_BINARY_INV + cv2.THRESH_OTSU)
# 寻找轮廓
contours, _ = cv2.findContours(thresholded, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
if contours:
for contour in contours:
# 计算轮廓的外接矩形
x, y, w, h = cv2.boundingRect(contour)
# 提取轮廓像素
contour_image = thresholded[y:y+h, x:x+w]
# 使用霍夫圆变换寻找可能的圆心点
circles = cv2.HoughCircles(contour_image, cv2.HOUGH_GRADIENT, dp=1, minDist=20, param1=50, param2=30, minRadius=0, maxRadius=0)
# 如果找到圆形,检查相邻像素的弧度差异
if circles is not None:
circles = np.round(circles[0, :]).astype("int")
for (x, y, r) in circles:
center = (x + x, y + y)
# 计算周围像素的弧度差
neighbors = contour_image[max(0, y-r):min(y+r+1, h), max(0, x-r):min(x+r+1, w)]
angles = np.arctan2(neighbors[1:] - neighbors[:-1], neighbors[1:, 0] - neighbors[:-1, 0])
# 可能的突变点即弧度差显著的位置
curvature_derivative = np.abs(np.diff(angles))
peak_positions = np.where(curvature_derivative > np.mean(curvature_derivative) * 0.8)[0]
peak_positions += x - r # 将像素坐标转换回原始图像位置
yield center, peak_positions
else:
print(f"No contours found in the image at {image_path}")
# 使用函数
for point_info in find_contour_curve_points('your_image_path.jpg'):
print(f"Detected curve change point: ({point_info[0][0]}, {point_info[0][1]}), neighboring peaks: {point_info[1]}")