Converts a html image map into a json array where (optionally) each coordinate is transformed into a percentage (0.0 -> 1.0) based on the given width and height.

html_image_map_to_json.py

#!/usr/bin/env python

from __future__ import division
import sys
import argparse
import xml.etree.ElementTree as ET
import os.path

py3 = sys.version_info[0] > 2   # Check if python2 or python3

parser = argparse.ArgumentParser(description="Convert a html image map to a json equivalent. (For use with 'http://imagemap-generator.dariodomi.de/')")
parser.add_argument('width', type=int, help='Width of the image to do the mapping for.')
parser.add_argument('height', type=int, help='Height of the image to do the mapping for.')
parser.add_argument('in_path', nargs='?', default=None, type=str,
                    help='Relative path to a file containing only the html image map. Omit to read from STDIN instead.')
parser.add_argument('out_path', nargs='?', default=None, type=str,
                    help='Relative file path to write json output to. Omit to print to STDOUT instead.')
parser.add_argument('--relative', action='store_true',
                    help='Transform absolute pixel coords into percentages in the rang 0.0 -> 1.0')

args = parser.parse_args(sys.argv[1:])

# If the destination file exists, ask whether to overwrite.
if args.out_path is not None and os.path.isfile(args.out_path):
    prompt = "{} already exists, overwrite? (Y/N): ".format(args.out_path)
    if py3:
        result = input(prompt)
    else:
        result = raw_input(prompt)
    if not result.startswith('Y') and not result.startswith('y'):
        print("[Aborting]")
        exit(2)

# Parse the data into element tree and get the root.
if args.in_path is None:
    try:
        root = ET.fromstring(sys.stdin.read())
    except ET.ParseError as e:
        print(e)
        exit(1)
else:
    try:
        root = ET.parse(args.in_path).getroot()
    except IOError as e:
        print(e)
        exit(1)

# Find the map tag (check root and its children)
if root.tag == 'map':
    mapElement = root
else:
    mapElement = root.find('map')

if mapElement is None:
    print("No map element found!")
    exit(1)

# Stores and transforms rectangle areas.
class Area:
    def __init__(self, tag, coord_list, precision=4):
        self.tag = tag
        self.precision = precision
        self.startX = coord_list[0]
        self.startY = coord_list[1]
        self.endX = coord_list[2]
        self.endY = coord_list[3]

    # Changes coords from absolute pixels to percentages in the range (0.0 -> 1.0)
    def transform(self, width, height):
        self.startX = round(self.startX / width, self.precision)
        self.startY = round(self.startY / height, self.precision)
        self.endX = round(self.endX / width, self.precision)
        self.endY = round(self.endY / height, self.precision)

    def __str__(self):
        return '{{"tag":"{}", "startX":{},"startY":{},"endX":{},"endY":{}}}'\
            .format(self.tag, self.startX, self.startY, self.endX, self.endY)

    def __repr__(self):
        return self.__str__()

areaList = []
# Find all areas of the map.
for area in mapElement.findall('area'):
    if area.attrib.get('shape') == 'rect':
        a = Area(area.attrib.get('title'), map(int, area.attrib.get('coords').split(',')))
        if args.relative:
            a.transform(args.width, args.height)    # Change absolute pixels into relative percentages
        areaList.append(a)
    elif args.out_path is not None: # Only output warning if not writing result to STDOUT
        print("Found {} shape, only rect is supported. Skipping: {}".format(area.attrib.get('shape'), area.attrib.get('coords')))

if args.out_path is None:
    print(areaList)
else:
    with open(args.out_path, 'w') as file:
        # Write the areas to file as a json array.
        file.write("{}".format(areaList))
        print("[Done]")