cv2.imdecode()函数从指定的内存缓存中读取数据,并把数据转换(解码)成图像格式;主要用于从网络传输数据中恢复出图像。
cv2.imencode()函数是将图片格式转换(编码)成流数据,赋值到内存缓存中;主要用于图像数据格式的压缩,方便网络传输。
imdecode()使用
从网络读取图像数据并转换成图片格式:
# -*- coding: utf-8 -*-
import numpy as np
import urllib
import cv2
url = 'http://www.pyimagesearch.com/wp-content/uploads/2015/01/google_logo.png'
resp = urllib.urlopen(url)
image = np.asarray(bytearray(resp.read()), dtype="uint8")
image = cv2.imdecode(image, cv2.IMREAD_COLOR)
cv2.imshow('URL2Image',image)
cv2.waitKey()
显示图片:
imencode()使用
将图片编码到缓存,并保存到本地:
# -*- coding: utf-8 -*-
import numpy as np
import urllib
import cv2
img = cv2.imread('0122.jpg')
# '.jpg'表示把当前图片img按照jpg格式编码,按照不同格式编码的结果不一样
img_encode = cv2.imencode('.jpg', img)[1]
# imgg = cv2.imencode('.png', img)
data_encode = np.array(img_encode)
str_encode = data_encode.tostring()
# 缓存数据保存到本地
with open('img_encode.txt', 'w') as f:
f.write(str_encode)
f.flush
imencode()+imdecode()使用
图片编码保存到本地,读取本地文件解码恢复成图片格式:
# -*- coding: utf-8 -*-
import numpy as np
import urllib
import cv2
img = cv2.imread('0122.jpg')
# '.jpg'表示把当前图片img按照jpg格式编码,按照不同格式编码的结果不一样
img_encode = cv2.imencode('.jpg', img)[1]
# imgg = cv2.imencode('.png', img)
data_encode = np.array(img_encode)
str_encode = data_encode.tostring()
# 缓存数据保存到本地,以txt格式保存
with open('img_encode.txt', 'w') as f:
f.write(str_encode)
f.flush
with open('img_encode.txt', 'r') as f:
str_encode = f.read()
nparr = np.fromstring(str_encode, np.uint8)
img_decode = cv2.imdecode(nparr, cv2.IMREAD_COLOR)
cv2.imshow("img_decode", img_decode)
cv2.waitKey()
或者:
# -*- coding: utf-8 -*-
import numpy as np
import urllib
import cv2
img = cv2.imread('0122.jpg')
# '.jpg'表示把当前图片img按照jpg格式编码,按照不同格式编码的结果不一样
img_encode = cv2.imencode('.jpg', img)[1]
# imgg = cv2.imencode('.png', img)
data_encode = np.array(img_encode)
str_encode = data_encode.tostring()
# 缓存数据保存到本地,以txt格式保存
with open('img_encode.txt', 'w') as f:
f.write(str_encode)
f.flush
with open('img_encode.txt', 'r') as f:
str_encode = f.read()
image = np.asarray(bytearray(str_encode), dtype="uint8")
image = cv2.imdecode(image, cv2.IMREAD_COLOR)
cv2.imshow('img_decode',image)
cv2.waitKey()