gcode-with-thumbnail-thumbnailer.py

#!/usr/bin/env python3
#
# gcode-with-thumbnail-thumbnailer.py - A Gnome 3 thumbnailer for gcode with an embedded thumbnail
#
#    Copyright (C) 2022 Peter Ellens <ellensp@hotmail.com>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/gpl>.

#    # Contains code from the jpg re-encoder thumbnail post processor script:
#    https://raw.githubusercontent.com/alexqzd/Marlin/Gcode-preview/Slicer%20post-processing%20scripts/PrusaSlicer_JPEG_Preview.py
#    and  https://github.com/MestreLion/icns-thumbnailer

import sys
import re
import base64
import io
import subprocess

try:
    from PIL import Image
except ImportError:
    subprocess.check_call([sys.executable, "-m", "pip", "install", "Pillow"])
    from PIL import Image

def install(package):
    subprocess.check_call([sys.executable, "-m", "pip", "install", package])

def make_thumbnail(inputname, outputname, size=0):
    try:
        sourceFile = sys.argv[1]

        # Read the ENTIRE g-code file into memory
        with open(sourceFile, "r") as f:
            lines = f.read()
        f.close()

        thumb_expresion = '; thumbnail begin.*?\n((.|\n)*?); thumbnail end'
        thumb_matches = re.findall(thumb_expresion, lines)

        if not thumb_matches:
            sys.stderr.write("Thumbnail data not found\n")
            return 1

        for idx, match in enumerate(thumb_matches):
           original = match[0]
           encoded = original.replace("; ", "")
           encoded = encoded.replace("\n", "")
           encoded = encoded.replace("\r", "")
           decoded = base64.b64decode(encoded)
           pixbuf = Image.open(io.BytesIO(decoded))

        if size:
            width, height = pixbuf.size
            if width > height:
                if width > size:
                    height = height * size / width
                    width  = size
            else:
                if height > size:
                    width  = width * size / height
                    height = size

            scaled = pixbuf.resize((int(width),int(height)), Image.LANCZOS)
        else:
            scaled = pixbuf

        scaled.save(outputname,'png')

    except GLib.GError as e:
        sys.stderr.write("%s:%d: %s\n" % (e.domain, e.code, e))
        return e.code

def main(argv):
    try:
        args = argv[1], argv[2], int((argv[3:4] or [0])[0])
        if len(argv) > 4: raise IndexError
    except (ValueError, IndexError):
        sys.stderr.write("Usage: %s inputfile outputfile [size]\n" % argv[0])
        return 1

    return make_thumbnail(*args)

if __name__ == '__main__':
    sys.exit(main(sys.argv))