trace.py

import os
import shutil
import requests
import base64

from flask import Flask
from flask import request
from flask import abort
from flask import send_file
from subprocess import call

app = Flask(__name__)


@app.route('/', methods=['POST'])
def image_from_body():
    cont = request.json
    if('url' in cont):
        data = cont['url']
        return trace(data, False)

    if('b64' in cont):
        data = cont['b64']
        data = data.split(',')[1]
        return trace(data, True) 
    


@app.route('/', methods=['GET'])
def image_from_url():
    return trace(request.args.get('url', type = str), False)



def trace(image_requested, is_base64):
    input_image_file = '/tmp/input'
    bmp_image_file = '/tmp/temp.bmp'
    svg_filename = '/tmp/trace.svg'
    
    if not is_base64:
        url = image_requested  
        if not url:
            return "please provide URL of image to trace with ?url="

        # Download image from URL
        response = requests.get(url, stream=True)
        with open(input_image_file, 'wb') as file:
            shutil.copyfileobj(response.raw, file)
        del response
    else:
        imgdata = base64.b64decode(image_requested)
        with open(input_image_file, 'wb') as f:
            f.write(imgdata)

    # Convert image to .bmp
    call('convert %s %s' % (input_image_file, bmp_image_file), shell=True)
    
    # Trace .bmp to .svg
    call('potrace %s -o %s --svg' % (bmp_image_file, svg_filename), shell=True)
    
    return send_file(svg_filename, mimetype='image/svg+xml')

@app.after_request
def cleanup(response):
    location = '/tmp/traces'
    if os.path.isdir(location):
        shutil.rmtree(location)
    return response

if __name__ == "__main__":
    app.run(host='0.0.0.0',port=8080)