/**
 * @license
 * Copyright 2021 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import { PointProvider } from './point_provider.js';
/**
 * Provides conversions needed for K-Means quantization. Converting input to
 * points, and converting the final state of the K-Means algorithm to colors.
 */
export declare class LabPointProvider implements PointProvider {
    /**
     * Convert a color represented in ARGB to a 3-element array of L*a*b*
     * coordinates of the color.
     */
    fromInt(argb: number): number[];
    /**
     * Convert a 3-element array to a color represented in ARGB.
     */
    toInt(point: number[]): number;
    /**
     * Standard CIE 1976 delta E formula also takes the square root, unneeded
     * here. This method is used by quantization algorithms to compare distance,
     * and the relative ordering is the same, with or without a square root.
     *
     * This relatively minor optimization is helpful because this method is
     * called at least once for each pixel in an image.
     */
    distance(from: number[], to: number[]): number;
}