import { addImage } from './interfaces/add-image.type';
import { ElementConfig } from './interfaces/element-config.interface';
export declare class JpPreloadService {
    observer: IntersectionObserver;
    onAdd: addImage;
    tracked: Map<HTMLElement, ElementConfig>;
    defaultOptions: IntersectionObserverInit;
    initialize(options?: IntersectionObserverInit): void;
    onIntersection(entries: any): void;
    addImage(element: HTMLElement, config: ElementConfig): void;
    load(element: HTMLElement, elemConfig?: ElementConfig): void;
    private addImageToSet;
    private addImageFallbackToSet;
}