OpenCV数字图像处理基础

图片操作：载入，保存，展示

• 准备工作：下载一张图片picture.jpg

import numpy as np
import cv2

#查看cv2的版本
print(cv2.__version__)
#读取图片信息，展示图片
img = cv2.imread('./picture.jpg')
print(img)
print(img.shape)
cv2.imshow('img_show',img)
#输入任意键退出显示图片的窗口
key = cv2.waitKey(0)&0xff
print(key)
#将图片变为单色，并保存
img = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
print(img.shape)
cv2.imwrite('picture1.jpg',img)
#释放资源，与imshow()方法对应
cv2.destroyAllWindows()

• picture.jpg
  
• picture1.jpg

OpenCV绘图

• 准备工作：下载一张背景图片background.jpg

import numpy as np
import cv2

img = cv2.imread('./background.jpg')
print(img)
print(img.shape)
#直线
img = cv2.line(img,(0,0),(1280,0),(255,0,155),15)
img = cv2.line(img,(0,0),(0,800),(255,0,155),15)
img = cv2.line(img,(1280,0),(1280,800),(255,0,155),15)
img = cv2.line(img,(0,800),(1280,800),(255,0,155),15)
img = cv2.line(img,(100,100),(250,250),(255,255,255),3)
img = cv2.line(img,(250,100),(100,250),(255,255,255),3)
#矩形
img = cv2.rectangle(img,(100,100),(250,250),(0,255,255),3)
#圆形
img = cv2.circle(img,(175,175),110,(255,255,0),3)

cv2.imshow('img_show',img)
key = cv2.waitKey(0)&0xff
print(key)
cv2.destroyAllWindows()

• 绘图后的结果：
  

OpenCV文字处理

• 准备工作：下载一张背景图片background.jpg

import numpy as np
import cv2

img = cv2.imread('./background.jpg')
print(img)
print(img.shape)

'''
#直线
img = cv2.line(img,(0,0),(1280,0),(255,0,155),15)
img = cv2.line(img,(0,0),(0,800),(255,0,155),15)
img = cv2.line(img,(1280,0),(1280,800),(255,0,155),15)
img = cv2.line(img,(0,800),(1280,800),(255,0,155),15)
img = cv2.line(img,(100,100),(250,250),(255,255,255),3)
img = cv2.line(img,(250,100),(100,250),(255,255,255),3)
#矩形
img = cv2.rectangle(img,(100,100),(250,250),(0,255,255),3)
#圆形
img = cv2.circle(img,(175,175),110,(255,255,0),3)

'''

font = cv2.FONT_HERSHEY_SIMPLEX
cv2.putText(img,'Never frown',(750,150),font,1.5,(255,255,255),5,cv2.LINE_AA)
cv2.putText(img,'even when you are sad ',(625,250),font,1.5,(255,255,255),5,cv2.LINE_AA)
cv2.putText(img,'because you never know ',(500,350),font,1.5,(255,255,255),5,cv2.LINE_AA)
cv2.putText(img,'who is falling in love with your smile ',(390,450),font,1.5,(255,255,255),5,cv2.LINE_AA)



cv2.imshow('img_show',img)
key = cv2.waitKey(0)&0xff
print(key)
cv2.destroyAllWindows()

• 文字处理结果
  

• 原始图片background.jpg
  

• 文字+绘图后的结果：