export type LAB = [L: number, a: number, b: number];
export interface CMC {
    lightness?: number;
    chroma?: number;
}
export interface CIE94 {
    lightness?: 1 | 2;
    chroma?: number;
    hue?: number;
}
export interface CIEDE2000 {
    lightness?: number;
    chroma?: number;
    hue?: number;
}
/**
 * The CIE76 color difference algorithm: Euclidean distance in LAB space.
 * https://en.wikipedia.org/wiki/Color_difference#CIE76
 */
export declare function getDeltaE_CIE76(x1: LAB, x2: LAB): number;
/**
 * The CMC l:c (1984) color difference algorithm.
 * https://en.wikipedia.org/wiki/Color_difference#CMC_l:c_(1984)
 */
export declare function getDeltaE_CMC([L1, a1, b1]: LAB, [L2, a2, b2]: LAB, weights?: CMC): number;
/**
 * The CIE94 color difference algorithm.
 * https://en.wikipedia.org/wiki/Color_difference#CIE94
 */
export declare function getDeltaE_CIE94([L1, a1, b1]: LAB, [L2, a2, b2]: LAB, weights?: CIE94): number;
/**
 * The CIEDE2000 color difference algorithm.
 * https://en.wikipedia.org/wiki/Color_difference#CIEDE2000
 */
export declare function getDeltaE_CIEDE2000([L1, a1, b1]: LAB, [L2, a2, b2]: LAB, weights?: CIEDE2000): number;