import { RGBA } from 'color-blend/dist/types';
import { NdArray } from 'ndarray';
import { Shape } from '../shapes/Shape';
export declare const backgroundColor: (image: any) => RGBA;
/**
 * Calculates the necessary color to move current closer to target
 */
export declare const scanlineColor: (target: NdArray, current: NdArray, scanlines: number[][], alpha: number) => RGBA;
/**
 * Calculates the root-mean-square error between two images
 */
export declare const differenceFull: (one: NdArray, two: NdArray) => number;
/**
 * Calculates the root-mean-square error between the parts of the two images within the scanlines
 */
export declare const differencePartial: (target: NdArray, before: NdArray, after: NdArray, score: number, scanlines: number[][]) => number;
/**
 * Calculates a measure of the improvement adding the shape provides, lower energy is better
 */
export declare const energy: (shape: Shape, alpha: number, target: NdArray, current: NdArray, buffer: NdArray, score: number) => number;