ZeroMQ pyzmq send jpeg image over tcp

Question

I am trying to send a jpeg image file through a ZeroMQ connection with pyzmq, but the output is 3 times the size of the input, and no longer a valid jpeg. I load the image and send with...

f = open("test1.jpg",'rb')
strng = f.read()
socket.send(strng)
f.close()

I receive and save with...

message = socket.recv()
f = open("test2.jpg", 'w')
f.write(str(message))
f.close()

I am new to zmq, and I could not find any info on sending images. Has anyone sent images through ZeroMQ, or have any ideas on how to find the problem?

Answer 1

Before sending the file you can "base64" encode it and decode it when received.

Sending:

import base64
f = open("test1.jpg",'rb')
bytes = bytearray(f.read())
strng = base64.b64encode(bytes)
socket.send(strng)
f.close()

Receiving:

import base64
message = socket.recv()
f = open("test2.jpg", 'wb')
ba = bytearray(base64.b64decode(message))
f.write(ba)
f.close()

Answer 2

You can try imagezmq. It's specially built for transporting images using PyZMQ messaging.

Sender

import socket
import imagezmq

sender = imagezmq.ImageSender(connect_to='tcp://receiver_name:5555')

sender_name = socket.gethostname() # send your hostname with each image

image = open("test1.jpg",'rb')
sender.send_image(sender_name, image)

Receiver

import imagezmq

image_hub = imagezmq.ImageHub()

sender_name, image = image_hub.recv_image()
image_hub.send_reply(b'OK')