opencv学习

1. 安装
   windows下python环境最方便的就是直接 pip install opencv-python

2. 图片质量

import cv2
img= cv2.imread('image0.JPG',1)
cv2.imwrite('imageMyTest.jpg', img,[cv2.IMWRITE_JPEG_QUALITY,0]) # arg3:图片质量，jpg为有损压缩

img= cv2.imread('image0.JPG',1)
cv2.imwrite('imageMyTest.png', img,[cv2.IMWRITE_PNG_COMPRESSION,0]) # arg3:图片质量，png为无损压缩 
# jpg 为0的时候压缩比高（0~100），png为0的时候压缩比低（0~9）

像素操作

import cv2
img = cv2.imread('image0.jpg',1)
(b,g,r) = img[100,100]
print(b,g,r)# bgr
#10 100 --- 110 100
for i in range(1,100):
    img[10+i,100] = (255,0,0)
cv2.imshow('image',img)
cv2.waitKey(0) #1000 ms