three.js/examples/jsm/loaders/KTXLoader.d.ts

import {
  LoadingManager,
  CompressedTextureLoader,
  PixelFormat,
  CompressedPixelFormat
} from '../../../src/Three';

export interface KTX {
  mipmaps: object[];
  width: number;
  height: number;
  format: PixelFormat | CompressedPixelFormat;
  mipmapCount: number;
  isCubemap: boolean;
}

export class KTXLoader extends CompressedTextureLoader {
  constructor(manager?: LoadingManager);

  parse(buffer: ArrayBuffer, loadMipmaps: boolean) : KTX;
}