opencv常用操作

1、imdecode()与imencode() 图片的解码与编码

"""
图片解码
"""
import cv2
import numpy as np
import requests

image_url = "https://bkimg.cdn.bcebos.com/pic/0823dd54564e92581460604f9082d158ccbf4e3f?x-bce-process=image/watermark,image_d2F0ZXIvYmFpa2U5Mg==,g_7,xp_5,yp_5"
r = requests.get(image_url)
img = np.asarray(bytearray(r.content), dtype='uint8')
img = cv2.imdecode(img, cv2.IMREAD_COLOR)  # 将数据解码为图片格式
# cv2.imshow('Crystal', img)
# cv2.waitKey()
cv2.imwrite("Crystal.jpg", img)

"""
图片编码
"""
import numpy as np
import urllib
import cv2

img = cv2.imread("Crystal.jpg")
img_bin_jpg = cv2.imencode('.jpg', img)
# img_bin_png = cv2.imencode('.png', img)  #不同格式图片
# print(img_bin_jpg)
data_encode = np.array(img_bin_jpg)
str_encode = data_encode.tostring()
print(str_encode)