This is a command line interface for dithering images using the hitherdither library.

Setup:

1. Install python3
2. cd into the folder which this file is stored and create a folder called output
3. Use pip to install the requirements from requirements.txt, the command pip install -r requirements.txt should work
4. Now run python dither.py --help to show all the options available

Arguments:

Image

-i or --image
Path to the image you wish to dither. If you do not give the absolute path, it must be either within the same folder as this script or a subfolder. This command is the only one that is always required.

Example: python dither.py -i myimage.png

Dither

-d or --dither
The name of the dithering algorithm you wish to use. The default will be bayer dithering.
Available choices:

1. bayer or b
2. yliluoma or y
3. cluster-dot or cd
4. floyd-steinberg or fs
5. jarvis-judice-ninke or jjn

Example: python dither.py --image input/mycoolimage.png -d yliluoma

Palette

-p or --palette
Name of the palette you wish to dither with. The default palette is geo32. If you want to add more palettes, add them to the palettes.py file as a dictionary of string and rgb tuple pairs, and then go into dither.py and edit the choices of this arg to include the name that you give to your dictionary.
Available choices:

1. geo32
2. dawnbringer16
3. pixelcanvas
4. pixelzone
5. pxlsspace

Example: python dither.py -i /home/username/Pictures/myverycoolimage.jpg -p geo32

Threshold

-t or --threshold
The threshold value you want to use for dithering. The default value is 128. Not all of these dithering algorithms take a threshold value as an argument.
Available choices:

1. 2
2. 4
3. 8
4. 16
5. 32
6. 64
7. 128
8. 256
9. 512

Order

-o or --order
The order value you want to use for dithering. The default value is 8.
Available choices:

1. 2
2. 4
3. 8
4. 16
5. 32

Exclude

-e or --exclude
The colours that you do not want to use from whichever palette you are using. The default value is 0, which removes no colours. To see which number corresponds to each palette's colours, look in palettes.py.

Example: python dither.py -i input/myverycoolimage.png -p geo32 -e 5 8 89 Here the colours 5 and 8 would not be used in dithering, and the input 89 would be ignored, as it isn't a valid colour number.