three.js/src/loaders/ImageLoader.d.ts

import { Loader } from './Loader';
import { LoadingManager } from './LoadingManager';

/**
 * A loader for loading an image.
 * Unlike other loaders, this one emits events instead of using predefined callbacks. So if you're interested in getting notified when things happen, you need to add listeners to the object.
 */
export class ImageLoader extends Loader {

	constructor( manager?: LoadingManager );

	load(
		url: string,
		onLoad?: ( image: HTMLImageElement ) => void,
		onProgress?: ( event: ProgressEvent ) => void,
		onError?: ( event: ErrorEvent ) => void
	): HTMLImageElement;

}