Mastering OpenCV 4 with Python

A minimal example to introduce OpenCV and Flask

Script hello_opencv.py is coded in order to show how you can use OpenCV to perform a very basic web computer vision application. The code of this script is shown next:

# Import required packages:import cv2from flask import Flask, request, make_responseimport numpy as npimport urllib.requestapp = Flask(__name__)@app.route('/canny', methods=['GET'])def canny_processing():    # Get the image:    with urllib.request.urlopen(request.args.get('url')) as url:        image_array = np.asarray(bytearray(url.read()), dtype=np.uint8)    # Convert the image to OpenCV format:    img_opencv = cv2.imdecode(image_array, -1)    # Convert image to grayscale:    gray = cv2.cvtColor(img_opencv, cv2.COLOR_BGR2GRAY)    # Perform canny edge ...