一、opencv快速入门

1、安装和简单demo

• 安装 pip3 install opencv-python 和 pip3 install opencv-contrib-python 可以指定版本
• first demo

import cv2

img = cv2.imread("cat.jpeg")

def showImg(name, img):
    cv2.imshow(name, img)
    cv2.waitKey(0)
    cv2.destoryAllWindows()

showImg("img", img)

2、读取操作

• 读取图片

  import cv2
  
  img = cv2.imread("cat.jpeg")
  

• 读取视频

  import cv2
  
  vc = cv2.VideoCapture('test.mp4')
  if vc.isOpened():
      open, frame = vc.read()
  else:
      open = False
  while open:
      ret, f = vc.read()
      if f is None:
          break
      if ret == True:
          gray = cv2.cvtColor(f, cv2.COLOR_BGR2GRAY)
          cv2.imshow('result', gray)
          if cv2.waitKey(30) & 0xFF == 27:
              break
  vc.release()
  cv2.destroyAllWindows()
  

二、图片的操作

1、截取图片 ROI区域

import cv2

img = cv2.imread("cat.jpeg")
img = img[0:200,0:200]//直接使用切片即可

2、边界填充

3、数值计算

4、图像阈值

5、