Convertron3000 is a graphics converter for Commodore 64 computers. It runs on Linux, MacOS, Windows and other systems supported by Python.
| reason | description |
|---|---|
| open source | easy to modify and to improve, any useful contribution is highly welcome |
| portable | available on Linux, MacOS, Windows and any other system supported by Python3 |
| instant preview | just fiddle around with the sliders and see the result before converting |
| deal with color clashes | visualize color clashes instantly or read out their position from an optional json-file |
- fieserWolF/Abyss-Connection - initial work - https://github.com/fieserWolF https://csdb.dk/scener/?id=3623
- thanks to Green/ATW for spontaneously naming Convertron3000 :)
- thanks to people on csdb.dk for commenting and giving ideas how to improve
- thanks to Henrik Blidh for his hitherdither library https://github.com/hbldh/hitherdither which I use
Using Convertron3000 is pretty straight-forward:
- Open some image.
- Adjust the sliders or apply an effect.
- Convert to koala or hires format.
- optional: Check position of color-clashes.
- Save the resulting image.
| key | function |
|---|---|
| F1 | help |
| Alt-o | open image |
| Alt-s | save image (koala or hires format) |
| Alt-c | convert image |
| Alt-p | open settings |
| Alt-v | save settings |
| Alt-q | quit |
As of now, Convertron3000 offers various dithering methods. As the PIL-library only implements "floyd-steinberg"-dithering, all other dithering methods were taken from the hitherdither library.
| reason | description |
|---|---|
| floyd-steinberg dithering | speedy performance from the PIL-library |
| bayer-ordered dithering | the speedy standard, my favourite for C64 pictures |
| line dithering | a modified bayer-ordered dithering method, sometimes looks better than normal ordered dithering |
| dot dithering | not my favourite, but might give nice results on some pictures |
| yliluomas1 dithering | Warning: Painfully slow - use with care! The results are stunningly good sometimes, though. |
Please, take note that all dithering implementations except "floyd-steinberg"-dithering are quite slow when using the "Brightness palette"-mode, which is described below.
Sometimes converted images look better when applying a palette based on brightness values.
- Select "brightness palette" mode.
- Choose one of the presets ("purple", "brown" etc.).
You can also create your own palette like this:
- Edit the .json file: In the .json file you specify the size of your palette and the C64-colors like in one of the examples provided.
- Open your .json file. You find this option in the drop-down menu under "open custom gradient".
- Choose "custom" as your brightness palette.
The multicolor bitmap is stored in the widely-spread KoalaPainter (.koa) format:
- 2 bytes load address
- 8000 bytes raw bitmap data
- 1000 bytes raw "Video Matrix" (screen) data
- 1000 bytes raw "Color RAM" data
- 1 byte background data
The hires bitmap is stored in the widely-spread Advanced Art Studio (.art) format:
- 2 bytes load address
- 8000 bytes raw bitmap data
- 1000 bytes raw "Video Matrix" (screen) data
CONVERTRON3000 v1.34 [build 251229-205604] *** by fieserWolF
usage: convertron.py [-h] [-i INPUT_IMAGE] [-g FILE_GRADIENT] [-s FILE_SETTINGS] [-d]
This program reads an image-file, lets the user adjust settings and converts it to a C64 koala or hires image.
options:
-h, --help show this help message and exit
-i, --image INPUT_IMAGE
image file)
-g, --gradient FILE_GRADIENT
filename of custom gradient file (JSON) to be loaded
-s, --settings FILE_SETTINGS
filename of settings file (JSON) to be loaded
-d, --debug show color-clashes on consule
Example: ./convertron.py -i image.png -g 8color_gradient-brown.json -s settings.json -d
Convertron3000 comes in two flavors:
- Python3 script if you have python3 installed on your system (preferred method)
- executable for Linux and Windows (see releases)
Just download your zip-bundle at releases, extract it to a folder of your choice and enjoy.
If some antivirus scanner puts Convertron3000 into quarantine because it suspects a trojan or virus, simply put it out there again. It isn`t harmful, I used PyInstaller to bundle the standalone executable for you. Unfortunately, the PyInstaller bootloader triggers a false alarm on some systems. I even tried my best and re-compiled the PyInstaller bootloader so that this should not happen anymore. Keep your fingers crossed ;)
In releases you also find older versions of Convertron 3000 compiled as standalone executables. You may use this, but your system might complain that the code is not signed by a certificated developer. Well, I am not, so I signed the program on my own.
"Convertron3000" can`t be opened because it is from an unidentified developer.
You need to right-click or Control-click the app and select “Open”.
At least this is needed to run the script directly:
- python 3
- python tkinter module
- python "The Python Imaging Library" (PIL)
- python "argparse" library
- python "hitherdither" library
Normally, you would use pip like this:
pip3 install pillow argparse git+https://www.github.com/hbldh/hitherdither
You might need to install git (apt install git) first.
On my Debian GNU/Linux machine I use apt-get to install everything needed:
apt update
apt install python3 python3-tk python3-pil python3-pil.imagetk
pip3 install git+https://www.github.com/hbldh/hitherdither
- Go to https://github.com/fieserWolF/convertron3000.
- Click on the green "Code" button and "Download ZIP".
- Extract the downloaded ZIP-file to any folder.
- custom brightness palette editor
Any help and support in any form is highly appreciated.
If you have a feature request, a bug report or if you want to offer help, please, contact me:
http://csdb.dk/scener/?id=3623 or wolf@abyss-connection.de
- resizable image windows
- various bug fixes
- all settings can now be written to a file and restored to a file (json format)
- rearranged the main layout to simplify the workflow (all controls are closer by now)
- rewritten the whole code, split up into parts
- rearranged the documentation
- responsive GUI
- bug fix: proper file-not-found handling when opening images
- bug fix: fixed crash when not finding reasonable color replacement in hires mode (thanks slesinger for the bug report)
- added: color-clashes can be saved as image and as json
- bug fixes
- added proper commandline argument parsing (try "convertron.py --help")
- added json output of color clashes (can be read from other tools to work on color clashes)
- fixed: removed leftover saving debug image "/tmp/1.png"
- fixed: wrong hires image dimensions when using line dithering
- fixed: proper scaling, better conversion
- show position of color clashes in GUI and on console
- proper dithering support: bayer-ordered, line dither and some others
- GUI improvements
- moved standalone executables to releases
- transfered whole code to Python3
- great speed improvement, converts much faster now
- new feature: specify image on the command-line, e.g. "convertron.py picture.jpg"
- standalone executables for 64bit-systems: Linux, Darwin (MacOS) and Windows
- GUI design adjusted for MacOS/Darwin
- numpy library not used any more
- documentation
- custom brightness palette now uses .json format
- added licenses
- added to github with proper README.md
- hires mode
- colodore palette
- button: reset color modifiers to default
- start address now in hex
- custom brightness palette (config file)
- initial release
Convertron3000 is a graphics converter for Commodore 64 computers.
Copyright (C) 2026 fieserWolF / Abyss-Connection
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/.
See the LICENSE file for details.
For further questions, please contact me at http://csdb.dk/scener/?id=3623 or wolf@abyss-connection.de
For Python3, The Python Imaging Library (PIL), Tcl/Tk and other used source licenses see file LICENSE_OTHERS.