python-opencv在有噪音的情况下提取图像的轮廓实例

img = cv2.imread("temp.jpg")    #载入图像
h, w = img.shape[:2]      #获取图像的高和宽 
cv2.imshow("Origin", img) 

blured = cv2.blur(img,(5,5))    #进行滤波去掉噪声
cv2.imshow("Blur", blured)     #显示低通滤波后的图像

gray = cv2.cvtColor(blured,cv2.COLOR_BGR2GRAY) 
cv2.imshow("gray", gray) 

#定义结构元素 
kernel = cv2.getStructuringElement(cv2.MORPH_RECT,(50, 50))
#开闭运算，先开运算去除背景噪声，再继续闭运算填充目标内的孔洞
opened = cv2.morphologyEx(gray, cv2.MORPH_OPEN, kernel) 
closed = cv2.morphologyEx(opened, cv2.MORPH_CLOSE, kernel) 
cv2.imshow("closed", closed)

#找到轮廓
_,contours, hierarchy = cv2.findContours(binary,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE) 
#绘制轮廓
cv2.drawContours(img,contours,-1,(0,0,255),3) 
#绘制结果
cv2.imshow("result", img)

#coding=utf-8 
import cv2 
import numpy as np

img = cv2.imread("temp.jpg")    #载入图像
h, w = img.shape[:2]      #获取图像的高和宽 
cv2.imshow("Origin", img)     #显示原始图像

blured = cv2.blur(img,(5,5))    #进行滤波去掉噪声
cv2.imshow("Blur", blured)     #显示低通滤波后的图像

mask = np.zeros((h+2, w+2), np.uint8)  #掩码长和宽都比输入图像多两个像素点，满水填充不会超出掩码的非零边缘 
#进行泛洪填充
cv2.floodFill(blured, mask, (w-1,h-1), (255,255,255), (2,2,2),(3,3,3),8)
cv2.imshow("floodfill", blured) 

#得到灰度图
gray = cv2.cvtColor(blured,cv2.COLOR_BGR2GRAY) 
cv2.imshow("gray", gray) 


#定义结构元素 
kernel = cv2.getStructuringElement(cv2.MORPH_RECT,(50, 50))
#开闭运算，先开运算去除背景噪声，再继续闭运算填充目标内的孔洞
opened = cv2.morphologyEx(gray, cv2.MORPH_OPEN, kernel) 
closed = cv2.morphologyEx(opened, cv2.MORPH_CLOSE, kernel) 
cv2.imshow("closed", closed) 

#求二值图
ret, binary = cv2.threshold(closed,250,255,cv2.THRESH_BINARY) 
cv2.imshow("binary", binary) 

#找到轮廓
_,contours, hierarchy = cv2.findContours(binary,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE) 
#绘制轮廓

cv2.drawContours(img,contours,-1,(0,0,255),3) 
#绘制结果
cv2.imshow("result", img)

cv2.waitKey(0) 
cv2.destroyAllWindows()