一张图片中有使用cv2.line（）画的不规则图像，写一段代码，计算该不规则图形中的像素点个数和总的像素点个数之比，Python语言

import cv2

# 读取图像
img = cv2.imread("irregular_shape.jpg")

# 将图像转为灰度图
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

# 二值化处理
_, thresh = cv2.threshold(gray, 127, 255, cv2.THRESH_BINARY)

# 使用cv2.findContours()函数提取轮廓
contours, _ = cv2.findContours(thresh, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)

# 绘制轮廓
cv2.drawContours(img, contours, -1, (0, 0, 255), 3)

# 统计像素点个数
total_pixels = img.shape[0] * img.shape[1]
irregular_pixels = cv2.countNonZero(thresh)

# 计算比值
ratio = irregular_pixels / total_pixels

# 显示结果
cv2.imshow("image", img)
print("不规则图形像素点个数：", irregular_pixels)
print("总像素点个数：", total_pixels)
print("比值：", ratio)
cv2.waitKey(0)
cv2.destroyAllWindows()