/**
 * RGB color representation
 */
interface RGB {
    r: number;
    g: number;
    b: number;
}
/**
 * Image buffer in RGBA format
 * Compatible with Canvas ImageData and Node.js image libraries
 */
interface ImageBuffer {
    width: number;
    height: number;
    data: Uint8ClampedArray;
}
/**
 * Palette-indexed image output
 */
interface PaletteImageBuffer {
    width: number;
    height: number;
    indices: Uint8Array;
    palette: RGB[];
}
/**
 * Color palette definition
 */
interface ColorPalette {
    readonly colors: Record<string, RGB>;
    readonly accent: string;
    /** Canonical firmware color scheme value, if this is a measured palette. */
    readonly scheme?: number;
}

/**
 * Dithering algorithm modes
 * Values match firmware conventions (0-9)
 */
declare enum DitherMode {
    /**
     * Direct nearest-color mapping with no error diffusion. Intended for
     * already-quantized graphics only. On limited palettes (especially BWR),
     * continuous-tone photos or large flat mid-tone areas can map to an
     * unexpected ink (e.g. a mid-gray region rendered as solid red); use an
     * error-diffusion mode (e.g. FLOYD_STEINBERG, BURKES) for photographic input.
     */
    NONE = 0,
    BURKES = 1,
    ORDERED = 2,
    FLOYD_STEINBERG = 3,
    ATKINSON = 4,
    STUCKI = 5,
    SIERRA = 6,
    SIERRA_LITE = 7,
    JARVIS_JUDICE_NINKE = 8,
    /**
     * Error diffusion with pseudo-random traversal instead of a raster scan,
     * diffusing error only to not-yet-quantized neighbours. Produces no
     * directional structure. `serpentine` is ignored: there is no scan direction.
     */
    DIZZY = 9
}

declare const SPECTRA_7_3_6COLOR: ColorPalette;
declare const SPECTRA_7_3_6COLOR_V2: ColorPalette;
declare const MONO_4_26: ColorPalette;
declare const BWRY_4_2: ColorPalette;
declare const BWRY_3_97: ColorPalette;
declare const SOLUM_BWR: ColorPalette;
declare const HANSHOW_BWR: ColorPalette;
declare const HANSHOW_BWY: ColorPalette;

/**
 * E-paper display color schemes.
 *
 * Integer values are a firmware wire contract. Canonical source of truth:
 * `enum ColorScheme` in `opendisplay-protocol/src/opendisplay_structs.h`, which
 * names `packages/rust/core/src/palettes.rs` as its designated mirror.
 */
declare enum ColorScheme {
    MONO = 0,
    BWR = 1,
    BWY = 2,
    BWRY = 3,
    BWGBRY = 4,
    GRAYSCALE_4 = 5,
    GRAYSCALE_16 = 6,
    /**
     * 7-color Spectra/ACeP. Protocol v2 reassigned value 7 from the former
     * GRAYSCALE_8 to SEVEN_COLOR; GRAYSCALE_8 now lives at library-local value 9
     * (below). Ink order is BWGBRY plus orange, matching the bb_epaper logical
     * ink indices.
     */
    SEVEN_COLOR = 7,
    /** Spectra 6 nibbles, left-half plane then right-half plane (dual-CS panels). */
    BWGBRY_SPLIT = 8,
    /**
     * 8-level grayscale dithering target, e.g. the Inkplate 10 (issue #19).
     *
     * Value 9 is NOT a firmware wire value. `opendisplay_structs.h` defines
     * `enum ColorScheme` values 0-8 and 100-102 only; it has no value 9 and none
     * is expected to be assigned here. This variant exists purely so the
     * dithering library can target 8-level-gray panels outside the OpenDisplay
     * ecosystem. Never send this value to a device as a `color_scheme` field.
     */
    GRAYSCALE_8 = 9
}
/** Get color palette for a color scheme */
declare function getPalette(scheme: ColorScheme): ColorPalette;
/** Get number of colors in a color scheme */
declare function getColorCount(scheme: ColorScheme): number;
declare function fromValue(value: number): ColorScheme;

/**
 * Options for `ditherImage`. All fields are optional — defaults are sensible.
 *
 * Pre-processing pipeline (each step is a no-op at its identity value):
 * `exposure → saturation → shadows/highlights → tone → gamut → dither`.
 */
interface DitherOptions {
    /** Dithering algorithm. Default: `DitherMode.BURKES`. */
    mode?: DitherMode;
    /** Alternate row scan direction for error diffusion. Default: `true`. */
    serpentine?: boolean;
    /** Linear-RGB exposure multiplier. 1.0 = no change, 2.0 = +1 stop. Default: `1.0`. */
    exposure?: number;
    /** OKLab saturation multiplier. 1.0 = no change, 0.0 = grayscale. Default: `1.0`. */
    saturation?: number;
    /** Shadow lift strength (S-curve lower half). 0.0 = off, 1.0 = strong. Default: `0.0`. */
    shadows?: number;
    /** Highlight compression strength (S-curve upper half). 0.0 = off, 1.0 = strong. Default: `0.0`. */
    highlights?: number;
    /** Dynamic-range compression: `0.0`/`'off'` disables, `'auto'` opts in. Default: `0.0`. */
    tone?: number | 'auto' | 'off';
    /** Gamut compression: `0.0`/`'off'` disables, `'auto'` opts in. Default: `0.0`. */
    gamut?: number | 'auto' | 'off';
}
/**
 * Apply dithering to an RGBA image for an e-paper display.
 *
 * @param image     Input RGBA image. Alpha is composited on white.
 * @param palette   Target palette: `ColorScheme` enum (idealized) or `ColorPalette` (measured).
 * @param options   Per-call overrides — see {@link DitherOptions}.
 * @returns Palette-indexed image buffer.
 */
declare function ditherImage(image: ImageBuffer, palette: ColorScheme | ColorPalette, options?: DitherOptions): PaletteImageBuffer;

declare const VERSION = "0.1.0";

export { BWRY_3_97, BWRY_4_2, type ColorPalette, ColorScheme, DitherMode, type DitherOptions, HANSHOW_BWR, HANSHOW_BWY, type ImageBuffer, MONO_4_26, type PaletteImageBuffer, type RGB, SOLUM_BWR, SPECTRA_7_3_6COLOR, SPECTRA_7_3_6COLOR_V2, VERSION, ditherImage, fromValue, getColorCount, getPalette };