import cv2 as cv

import numpy as np

# 将图像中的像素值改为 255-原像素值

def access_pixels(image):

print(image.shape)

height = image.shape[0]

width = image.shape[1]

channels = image.shape[2]

print('width: %s, height: %s, channels: %s'%(width, height, channels))

# 三层循环逐个修改像素点

for row in range(height):

for col in range(width):

for c in range(channels):

pv = image[row, col, c]

image[row, col, c] = 255-pv

cv.imshow('pixel_demo', image)

# 作用等同于上面的access_pixels

def inverse(image):

dst = cv.bitwise_not(image)

cv.imshow('inverse demo', dst)

# 创建三通道、单通道图像

def creat_demo():

# img = np.zeros([400, 400, 3], np.uint8) # 三通道顺序是BGR

# # img[:, :, 0] = np.ones([400, 400]) * 255

# img[:, :, 2] = np.ones([400, 400])*255

# cv.imshow('new image', img)

#单通道

# img = np.ones([400, 400, 1], np.uint8) # 需要指明通道数1

# # img[:, :, 0] = np.ones([400, 400]) * 127

# img = img*127

# cv.imshow('new image', img)

# cv.imwrite('C:/Users/Y/Pictures/Saved Pictures/myImage.png', img)

m1 = np.ones([3, 3], np.uint8)

m1.fill(12222.388)

print(m1)

m2 = m1.reshape([1, 9])

print(m2)

src = cv.imread('C:/Users/Y/Pictures/Saved Pictures/demo.png')

cv.namedWindow('input image', cv.WINDOW_AUTOSIZE)

cv.imshow('input image', src)

t1 = cv.getTickCount()

inverse(src)

t2 = cv.getTickCount()

time = (t2-t1)/cv.getTickFrequency()

print('time: %s ms' % time*1000)

cv.waitKey(0)

cv.destroyAllWindows()