Ditherpy

ditherpy is a simple library for dithering. It implements both linearising the input image and a perception-corrected distance function. See this Stackoverflow thread for details on colour-correction.

You can provide a custom palette and toggle the colour-correction measures.

See obrhubr.org/dithering-in-colour for more details.

Usage

Install pip3 install numpy Pillow tqdm. Run python3 demo.py to generate two demo images, one of Dürer's "Young Hare" and a gradient.

The first image is the original, the second the linearised and third the non-linearised dithered image.

Usage as a library

Import from ditherpy import Dither.

• choose the colour space to use colour_space from "srgb"|"lin-srgb"|"oklab".
• choose the dithering diffusion matrix mode="Atkinson"|"FloydSteinberg".
• toggle a dynamic palette based on the image's colours dynamic_palette=True|False.

Load your image with Pillow into a numpy array, choose a palette and then run:

image = Image.open("input.jpg").convert("RGB")

# Choose a palette
# Array of arrays of RGB values
palette = np.array([[0, 0, 0], [255, 255, 255]])

dithered = Dither(options...).dither(image, palette)