python opencv将图片转为灰度图的方法示例

import cv2
import numpy as np

if __name__ == "__main__":
  img_path = "timg.jpg"
  img = cv2.imread(img_path)
  #获取图片的宽和高
  width,height = img.shape[:2][::-1]
  #将图片缩小便于显示观看
  img_resize = cv2.resize(img,
  (int(width*0.5),int(height*0.5)),interpolation=cv2.INTER_CUBIC)
  cv2.imshow("img",img_resize)
  print("img_reisze shape:{}".format(np.shape(img_resize)))

  #将图片转为灰度图
  img_gray = cv2.cvtColor(img_resize,cv2.COLOR_RGB2GRAY)
  cv2.imshow("img_gray",img_gray)
  print("img_gray shape:{}".format(np.shape(img_gray)))
  cv2.waitKey()

import cv2
import numpy as np

if __name__ == "__main__":
  img_path = "timg.jpg"
  img = cv2.imread(img_path)
  #获取图片的宽和高
  width,height = img.shape[:2][::-1]
  #将图片缩小便于显示观看
  img_resize = cv2.resize(img,
  (int(width*0.5),int(height*0.5)),interpolation=cv2.INTER_CUBIC)
  cv2.imshow("img",img_resize)
  print("img_reisze shape:{}".format(np.shape(img_resize)))

  #读取灰度图
  img_gray = cv2.imread(img_path,cv2.IMREAD_GRAYSCALE)
  #将图片缩小便于显示观看
  img_gray = cv2.resize(img_gray,
  (int(width*0.5),int(height*0.5)),interpolation=cv2.INTER_CUBIC)
  cv2.imshow("img_gray",img_gray)
  print("img_gray shape:{}".format(np.shape(img_gray)))
  cv2.waitKey()