/** Integer luminance per ALGORITHM.md §2. Inputs and result in 0..255. */
export declare const luma8: (r: number, g: number, b: number) => number;
/** Pack RGBA into a u32 with little-endian byte order r,g,b,a (ALGORITHM.md §11). */
export declare const packRGBA: (r: number, g: number, b: number, a?: number) => number;
export declare const unpackR: (c: number) => number;
export declare const unpackG: (c: number) => number;
export declare const unpackB: (c: number) => number;
export declare const unpackA: (c: number) => number;
export declare const rgbHex: (c: number) => string;