opencv学习笔记---用numpy对图片操作，创建，修改

# coding=GBK
import cv2 as cv
import numpy as np

def creat():
	image = np.zeros([400,400,3],np.uint8)#创建三通道的图片 blue green red 初始化为0
	image[:,:,0]=np.ones([400,400])*255#第一个通道全部变为一再乘以255  
	#image[:,:,0]前面不写表示全部的
	cv.imshow("hh",image)
	cv.waitKey(0)
	
def picture(image):
	print(image.shape)#高 宽 通道 
	print(image.size)#大小=高*宽*通道
	print(type(image))#字节
	print(image.dtype)#类型
	height=image.shape[0]
	width=image.shape[1]
	channels=image.shape[2]
	for row in range (height):#修改图片
		for col in range(width):
			for c in range(channels):
				pv=image[row,col,c]
				image[row,col,c]=255-pv
	cv.imwrite("D://demo.jpg",image)#修改后保存
     
	
	
image=cv.imread("D://img.jpg")
cv.imshow("qian",image)
picture(image)
cv.imshow("hou",image)

creat()
cv.waitKey(0)
cv.destroyAllWindows()

# coding=GBK
import cv2 as cv
import numpy as np

def inverse(image):
	dst=cv.bitwise_not(image)
	cv.imshow("inverse demo",dst)	
	
image=cv.imread("D://img.jpg")
t1=cv.getTickCount()
cv.imshow("qian",image)
inverse(image)#调用库函数
t2=cv.getTickCount()
time=(t2-t1)*1000/cv.getTickFrequency()
print("time: %s ms"%time)#计算时间

cv.waitKey(0)
cv.destroyAllWindows()