Canny边缘检测算法代码

以下是使用Python实现的Canny边缘检测算法代码：

import cv2
import numpy as np

def canny_edge_detection(image, sigma=0.33):
    # Convert the image to grayscale
    gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)

    # Calculate the median of the grayscale image
    median = np.median(gray)

    # Set the lower and upper thresholds using the median of the grayscale image
    lower_threshold = int(max(0, (1.0 - sigma) * median))
    upper_threshold = int(min(255, (1.0 + sigma) * median))

    # Apply Gaussian blur to reduce noise
    blurred = cv2.GaussianBlur(gray, (3, 3), 0)

    # Apply Canny edge detection with the lower and upper thresholds
    edges = cv2.Canny(blurred, lower_threshold, upper_threshold)

    return edges

该函数接受一个图像和一个可选的sigma参数作为输入，并返回一个包含边缘信息的二值图像。sigma参数用于计算Canny算法的阈值，可以调整Canny算法的敏感度。默认值为0.33，即使用中值滤波器计算的中值加减sigma倍数的值作为低阈值和高阈值。