/**
 * A cross-environment OCR {@link @nhtio/adk/batteries/media/contracts!MediaEngine}
 * backed by tesseract.js (WASM Tesseract — Node and browsers, no binary).
 *
 * @module @nhtio/adk/batteries/media/engines/tesseract_js
 *
 * @remarks
 * The local-by-default OCR engine. Language data files download on first use of each
 * language; point `langPath`/`cachePath` at a writable location to control where (the
 * factory requires `languages` up front so a deployment never silently fetches packs for
 * languages it didn't plan for). Workers are created per recognize call and terminated in
 * `finally` — slower than a pooled setup but leak-free by construction; consumers who need
 * pooling can BYO an engine that holds a worker.
 *
 * `tesseract.js` is an optional peer dependency, lazily imported on first actual use.
 *
 * Declares one convert capability: `image/*` to `txt`/`hocr`/`json` (OCR is a format
 * conversion — image in, text out). Language hints ride `request.options.languages`.
 */
import type * as TesseractNS from 'tesseract.js';
import type { MediaEngine } from "../contracts";
type TesseractModule = typeof TesseractNS;
/** Options for {@link tesseractJsEngine}. */
export interface TesseractJsEngineOptions {
    /** Languages to load, e.g. `['eng']`. REQUIRED — language packs download on first use. */
    languages: readonly string[];
    /** Where language data is fetched from / cached (forwarded to createWorker). */
    langPath?: string;
    /** Local cache directory for downloaded language data. */
    cachePath?: string;
    /** Override the module resolution. Default: `import('tesseract.js')`. */
    tesseract?: () => TesseractModule | Promise<TesseractModule>;
}
/**
 * Construct the tesseract.js OCR engine.
 *
 * @param options - Languages (required) and data-path overrides.
 * @returns The engine.
 */
export declare const tesseractJsEngine: (options: TesseractJsEngineOptions) => MediaEngine;
export {};