export declare const CONTRAST: {
    readonly R_COEFFICIENT: 0.2126;
    readonly G_COEFFICIENT: 0.7152;
    readonly B_COEFFICIENT: 0.0722;
    readonly GAMMA_THRESHOLD: 0.03928;
    readonly GAMMA_DIVISOR: 12.92;
    readonly GAMMA_OFFSET: 0.055;
    readonly GAMMA_MULTIPLIER: 1.055;
    readonly GAMMA_EXPONENT: 2.4;
};