@4bitlabs/color

A collection color manipulation functions and predefined palettes for working with EGA/CGA images.

Documentation

Full documentation for the library can be found here.

Palettes

Predefined Palettes

| Palette | | | ---------------------------- | ----------------------------------------------------------------------------------------------- | | Palettes.CGA_PALETTE | IBM's CGA Palette | | Palettes.TRUE_CGA_PALETTE | VileR's "True" CGA Palettte | | Palette.DGA_PALETTE | Adigun A. Polack's AAP-DGA16 | | Palette.COLLY_SOFT_PALETTE | collyflower05's SOFT CGA PALETTE |

Using your own Palette

const customPalette = Uint32Array.of(
  //AA-BB-GG-RR
  0xff_1f_1f_1f, // color 0
  /*        ...           */
  /* snip 14 more entries */
  /*        ...           */
  0xff_e0_e0_e0, // color 15
);

Predefined Dither Pairs

| Mix | Palette | Mix | | ----------------------- | -------- | ------------------------------ | | Dithers.CGA | CGA | none | | Dithers.CGA_MIX | CGA | 25% mix | | Dithers.CGA_FLAT | CGA | 50% mix (SCUMMVM de-dithering) | | Dithers.CGA_SOFT | CGA | Dynamic mix | | Dithers.TRUE_CGA | TRUE-CGA | none | | Dithers.TRUE_CGA_MIX | TRUE-CGA | 25% mix | | Dithers.TRUE_CGA_FLAT | TRUE-CGA | 50% mix (SCUMMVM de-dithering) | | Dithers.TRUE_CGA_SOFT | TRUE-CGA | Dynamic mix |

Generating your own Dither Pairs

import { Dithers, Mixers } from '@4bitlabs/color';

const pairs = Dithers.generatePairs(customPalette, Mixers.softMixer());

IBM 5153 Contrast Knob

import { IBM5153Contrast } from '@4bitlabs/color';

// Simulate turning the constrast knob on a IBM-5153 to about 50%
const palette = IBM5153Contrast(Palettes.CGA_PALETTE, 0.5);

Simulating Grayscale

const grays = toGrayscale(Palettes.CGA_PALETTE);