This code mainly realize is that using the Internet to transfer pictures, use on my Raspberry Pi project. The project runs on a PC server, running the client come in raspberry, both connected to the same local area network, change the IP address in the code, you can achieve the Raspberry Pi to collect real-time transmission of image data to the PC. To run server-side code, and then run the code to the client. Raspberry Pi camera to use an ordinary USB camera, and install opencv come in raspberry, raspberries come in opencv installation process can refer https://www.pyimagesearch.com/2017/09/04/raspbian -stretch-install-opencv-3-python-on-your-raspberry-pi /. Finally, the code can be slightly modified to transmit other information, of course, the server, the client can run on a PC, to validate the results. So the essence is still hope readers take this code can understand python's socket programming. Code Meaning has been described in detail in the notes for reference purposes only. Note that modifying the IP address and port number to use.
Server code
import socket
import time
import cv2
import numpy
def ReceiveVideo():
#IP地址'0.0.0.0'为等待客户端连接
address = ('0.0.0.0', 8002)
#建立socket对象，参数意义见https://blog.csdn.net/rebelqsp/article/details/22109925
#socket.AF_INET：服务器之间网络通信
#socket.SOCK_STREAM：流式socket , for TCP
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
#将套接字绑定到地址, 在AF_INET下,以元组（host,port）的形式表示地址.
s.bind(address)
#开始监听TCP传入连接。参数指定在拒绝连接之前，操作系统可以挂起的最大连接数量。该值至少为1，大部分应用程序设为5就可以了。
s.listen(1)
def recvall(sock, count):
buf = b''#buf是一个byte类型
while count:
#接受TCP套接字的数据。数据以字符串形式返回，count指定要接收的最大数据量.
newbuf = sock.recv(count)
if not newbuf: return None
buf += newbuf
count -= len(newbuf)
return buf
#接受TCP连接并返回（conn,address）,其中conn是新的套接字对象，可以用来接收和发送数据。addr是连接客户端的地址。
#没有连接则等待有连接
conn, addr = s.accept()
print('connect from:'+str(addr))
while 1:
start = time.time()#用于计算帧率信息
length = recvall(conn,16)#获得图片文件的长度,16代表获取长度
stringData = recvall(conn, int(length))#根据获得的文件长度，获取图片文件
data = numpy.frombuffer(stringData, numpy.uint8)#将获取到的字符流数据转换成1维数组
decimg=cv2.imdecode(data,cv2.IMREAD_COLOR)#将数组解码成图像
cv2.imshow('SERVER',decimg)#显示图像
#进行下一步处理
#。
#。
#。
#将帧率信息回传，主要目的是测试可以双向通信
end = time.time()
seconds = end - start
fps = 1/seconds;
conn.send(bytes(str(int(fps)),encoding='utf-8'))
k = cv2.waitKey(10)&0xff
if k == 27:
break
s.close()
cv2.destroyAllWindows()
if __name__ == '__main__':
ReceiveVideo()Client code:
import socket
import cv2
import numpy
import time
def SendVideo():
#建立sock连接
#address要连接的服务器IP地址和端口号
address = ('127.0.0.1', 8002)
try:
#建立socket对象，参数意义见https://blog.csdn.net/rebelqsp/article/details/22109925
#socket.AF_INET：服务器之间网络通信
#socket.SOCK_STREAM：流式socket , for TCP
sock = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
#开启连接
sock.connect(address)
except socket.error as msg:
print(msg)
sys.exit(1)
#建立图像读取对象
capture = cv2.VideoCapture(0)
#读取一帧图像，读取成功:ret=1 frame=读取到的一帧图像；读取失败:ret=0
ret, frame = capture.read()
#压缩参数，后面cv2.imencode将会用到，对于jpeg来说，15代表图像质量，越高代表图像质量越好为 0-100，默认95
encode_param=[int(cv2.IMWRITE_JPEG_QUALITY),15]
while ret:
#停止0.1S 防止发送过快服务的处理不过来，如果服务端的处理很多，那么应该加大这个值
time.sleep(0.01)
#cv2.imencode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
#'.jpg'表示将图片按照jpg格式编码。
result, imgencode = cv2.imencode('.jpg', frame, encode_param)
#建立矩阵
data = numpy.array(imgencode)
#将numpy矩阵转换成字符形式，以便在网络中传输
stringData = data.tostring()
#先发送要发送的数据的长度
#ljust() 方法返回一个原字符串左对齐,并使用空格填充至指定长度的新字符串
sock.send(str.encode(str(len(stringData)).ljust(16)));
#发送数据
sock.send(stringData);
#读取服务器返回值
receive = sock.recv(1024)
if len(receive):print(str(receive,encoding='utf-8'))
#读取下一帧图片
ret, frame = capture.read()
if cv2.waitKey(10) == 27:
break
sock.close()
if __name__ == '__main__':
SendVideo()