『python』OpenCV3计算机视觉库第二弹_简单的图片处理

 1 # coding=utf-8
 2 import cv2
 3 import numpy as np
 4 
 5 # array数组生成
 6 img = np.zeros((3,3),dtype=np.uint8)
 7 print img.shape
 8 
 9 # array数组转化为BGR模式
10 # 我也不懂为什么不用RGB而用BGB这么蹩脚的用法
11 img = cv2.cvtColor(img,cv2.COLOR_BAYER_BG2BGR)
12 print img.shape
13 
14 # 读取图片，左上像素点改写为蓝色，保存
15 img = cv2.imread(‘beauti.jpeg‘)
16 img[0][0] = [255,0,0]
17 cv2.imwrite(‘MyPic.png‘,img)
18 
19 # 丢失颜色信息，左上像素点改写为黑色，保存
20 img = cv2.imread(‘beauti.jpeg‘,cv2.IMREAD_GRAYSCALE)
21 print img.shape
22 img[0][0] = 0
23 cv2.imwrite(‘MyPic-gray.png‘,img)
24 
25 # 使用array.item和array.itemset优雅的重写上面代码
26 img = cv2.imread(‘beauti.jpeg‘,cv2.IMREAD_GRAYSCALE)
27 print img.shape
28 #img[0][0] = 0
29 print img.item(0,0)
30 img.itemset((0,0),0)
31 cv2.imwrite(‘MyPic-gray.png‘,img)
32 
33 # 去掉绿色通道
34 img = cv2.imread(‘beauti.jpeg‘)
35 img[:,:,1] = 0
36 cv2.imwrite(‘no_green.png‘,img)
37 print img.shape,img.size,img.dtype
38 
39 img = cv2.imread(‘beauti.jpeg‘)
40 # 显示图片，必须输入两个参数
41 cv2.imshow(‘my image‘,img)
42 # 窗口展示时间
43 cv2.waitKey()
44 # 释放窗口
45 cv2.destroyAllWindows()