index.ts

import { JimpClass } from "@jimp/types";
import { applyPaletteSync, buildPaletteSync, utils } from "image-q";
import z from "zod";

const QuantizeOptionsSchema = z.object({
  colors: z.number().optional(),
  colorDistanceFormula: z
    .union([
      z.literal("cie94-textiles"),
      z.literal("cie94-graphic-arts"),
      z.literal("ciede2000"),
      z.literal("color-metric"),
      z.literal("euclidean"),
      z.literal("euclidean-bt709-noalpha"),
      z.literal("euclidean-bt709"),
      z.literal("manhattan"),
      z.literal("manhattan-bt709"),
      z.literal("manhattan-nommyde"),
      z.literal("pngquant"),
    ])
    .optional(),
  paletteQuantization: z
    .union([
      z.literal("neuquant"),
      z.literal("neuquant-float"),
      z.literal("rgbquant"),
      z.literal("wuquant"),
    ])
    .optional(),
  imageQuantization: z
    .union([
      z.literal("nearest"),
      z.literal("riemersma"),
      z.literal("floyd-steinberg"),
      z.literal("false-floyd-steinberg"),
      z.literal("stucki"),
      z.literal("atkinson"),
      z.literal("jarvis"),
      z.literal("burkes"),
      z.literal("sierra"),
      z.literal("two-sierra"),
      z.literal("sierra-lite"),
    ])
    .optional(),
});

export type QuantizeOptions = z.infer<typeof QuantizeOptionsSchema>;

export const methods = {
  /**
   * Image color number reduction.
   */
  quantize<I extends JimpClass>(image: I, options: QuantizeOptions) {
    const {
      colors,
      colorDistanceFormula,
      paletteQuantization,
      imageQuantization,
    } = QuantizeOptionsSchema.parse(options);

    const inPointContainer = utils.PointContainer.fromUint8Array(
      new Uint8Array(image.bitmap.data.buffer),
      image.bitmap.width,
      image.bitmap.height
    );

    const palette = buildPaletteSync([inPointContainer], {
      colors,
      colorDistanceFormula,
      paletteQuantization,
    });
    const outPointContainer = applyPaletteSync(inPointContainer, palette, {
      colorDistanceFormula,
      imageQuantization,
    });

    image.bitmap.data = Buffer.from(outPointContainer.toUint8Array());

    return image;
  },
};