/// <reference types="node" />
import * as Jimp from 'jimp';
import Color = require('color');
import { WebManifestIcon } from './types/WebManifest';
export interface IconDefinition {
    dest: string;
    size: number;
}
export interface Icon {
    url: string;
    data: Jimp;
}
export declare class ImageHelper {
    private saveIcon;
    private generateCompositeImage;
    private getRoundedImage;
    private getMainColor;
    private updateBoundariesAndDetectInThreshold;
    private middle;
    private detectRoundPure;
    private cropRoundPureImage;
    private originalCropRoundPureImage;
    /**
     * Generate a file for the given icon inside targetDir.
     *
     * @param {Object} icon Object containing the original URL and the icon image data.
     * @param {string} targetDir Path to the directory the image will be saved in.
     * @param {Object} iconDef Icon definitions specifying the size the icon should be exported as.
     */
    generateIcon(icon: Icon, targetDir: string, iconDef: IconDefinition, backgroundColor?: Color, options?: {
        originalIcon: WebManifestIcon | null;
        transform: boolean;
    }): Promise<void>;
    /**
     * Set the color of a monochrome icon to be the theme color.
     *
     * @param {Object} icon Original monochrome icon to use.
     * @param {Color} themeColor Color to use for the icon.
     * @returns New image data.
     */
    monochromeFilter(icon: Icon, themeColor: Color): Promise<Icon>;
    /**
     * Fetches an Icon.
     *
     * @param {string} iconUrl the URL to fetch the icon from.
     * @returns an Object containing the original URL and the icon image data.
     */
    fetchIcon(iconUrl: string): Promise<Icon>;
    webp2PngBuffer(buffer: Buffer): Promise<Buffer>;
    fetchLocalIcon(localPath: any): Promise<Icon>;
}