import type { WatermarkImage, WatermarkText } from './type';
export default function generateBase64Url({ width, height, gapX, gapY, offsetLeft, offsetTop, rotate, alpha, watermarkContent, lineSpace, }: {
    width: number;
    height: number;
    gapX: number;
    gapY: number;
    offsetLeft: number;
    offsetTop: number;
    rotate: number;
    alpha: number;
    watermarkContent: WatermarkText | WatermarkImage | Array<WatermarkText | WatermarkImage>;
    lineSpace: number;
}, onFinish: (url: string) => void): string;
