import cv2

读取图像

src = cv2.imread(“page-2_0.jpg”)
if src is None:
print(“Fail to open image!”)
exit()

将图像转换为灰度图

gray = cv2.cvtColor(src, cv2.COLOR_BGR2GRAY)

# 全局二值化  
th = 180  # 阈值要根据实际情况调整  
binary = cv2.threshold(gray, th, 255, cv2.THRESH_BINARY)[1]  # 分割通道  
channels = cv2.split(src)  
red = channels[2]  
blue = channels[0]  
green = channels[1]  # 对红色通道进行二值化  
red_binary = cv2.threshold(red, th, 255, cv2.THRESH_BINARY)[1]  # 显示图像  
# cv2.imshow("src", src)  
# cv2.imshow("gray", gray)  
# cv2.imshow("binary", binary)  
cv2.imshow("red channel", red)  
# cv2.imwrite("red.jpg",red)
# cv2.imshow("blue channel", blue)  
# cv2.imshow("green channel", green)  
cv2.imshow("red+binary", red_binary)  # 等待按键  
cv2.waitKey(0)  
cv2.destroyAllWindows()