Compress png inside svg, in python v3. Based on https://gist.github.com/flesser/3f9c80ff42879cad41bf

run.sh

#!/bin/sh

# This is used to process multiple svg files

cp -r svg-original svg-compressed
cd svg-compressed

files=$(ls *.svg)
for file in $files
do
  echo $file start
  ../compress.py $file
  echo $file done
done

cd ..

svg-compress-embedded-png-v3.py

#! /usr/bin/env python3

import xml.etree.ElementTree as ET
import sys
import base64
import os
import io
from PIL import Image


PREFIX_PNG = "data:image/png;base64,"
PREFIX_JPG = "data:image/jpg;base64,"
ATTR = "{http://www.w3.org/1999/xlink}href"
DEFAULT_NS = "http://www.w3.org/2000/svg"

with open(sys.argv[1]) as svgfile:
    root = ET.parse(svgfile)
    file_id = 1
    base_name = os.path.splitext(sys.argv[1])[0]
    for e in root.findall(".//{%s}image" % DEFAULT_NS):
        href = e.get(ATTR)
        if href and href.startswith(PREFIX_PNG):
            pngimage = io.BytesIO()
            jpgimage = io.BytesIO()
            pngimage.write(base64.b64decode(href[len(PREFIX_PNG):]))
            Image.open(pngimage).save(jpgimage, "JPEG", quality=20)
            e.set(ATTR, PREFIX_JPG + base64.b64encode(jpgimage.getvalue()).decode("utf-8"))

root.write(sys.argv[1])