Skip to content

Instantly share code, notes, and snippets.

@kkoci kkoci/ forked from kylehounslow/
Created Dec 4, 2017

What would you like to do?
Send and receive images using Flask, Numpy and OpenCV
import requests
import json
import cv2
addr = 'http://localhost:5000'
test_url = addr + '/api/test'
# prepare headers for http request
content_type = 'image/jpeg'
headers = {'content-type': content_type}
img = cv2.imread('lena.jpg')
# encode image as jpeg
_, img_encoded = cv2.imencode('.jpg', img)
# send http request with image and receive response
response =, data=img_encoded.tostring(), headers=headers)
# decode response
print json.loads(response.text)
# expected output: {u'message': u'image received. size=124x124'}
from flask import Flask, request, Response
import jsonpickle
import numpy as np
import cv2
# Initialize the Flask application
app = Flask(__name__)
# route http posts to this method
@app.route('/api/test', methods=['POST'])
def test():
r = request
# convert string of image data to uint8
nparr = np.fromstring(, np.uint8)
# decode image
img = cv2.imdecode(nparr, cv2.IMREAD_COLOR)
# do some fancy processing here....
# build a response dict to send back to client
response = {'message': 'image received. size={}x{}'.format(img.shape[1], img.shape[0])
# encode response using jsonpickle
response_pickled = jsonpickle.encode(response)
return Response(response=response_pickled, status=200, mimetype="application/json")
# start flask app"", port=5000)
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.