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  • OpenCV-Python cv2.imdecode()和cv2.imencode() 图片解码和编码

    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()


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  • 原文地址:https://www.cnblogs.com/mtcnn/p/9411758.html
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