import type { Rectangle } from './ocr-engine';
import type { OcrWorker } from './ocr-worker';
/**
 * High-level async API for performing document image layout analysis and
 * OCR.
 */
export declare class OcrScheduler {
    private _workers;
    private _runningWorkers;
    constructor(workers: OcrWorker[]);
    private getWorker;
    destroy(): Promise<void>;
    /**
     * Load a trained model for a specific language. This can be specified either
     * as a URL to fetch or a buffer containing an already-loaded model.
     */
    loadModel(model: string | ArrayBuffer): Promise<void>;
    /**
     * Perform layout analysis and text recognition on the current image, if
     * not already done, and return the image's text as a string.
     */
    recognizeText(image: ImageBitmap | ImageData, rectangle?: Rectangle): Promise<string>;
    /**
     * Set the value of a Tesseract configuration variable.
     *
     * For a list of configuration variables, see
     * https://github.com/tesseract-ocr/tesseract/blob/677f5822f247ccb12b4e026265e88b959059fb59/src/ccmain/tesseractclass.cpp#L53
     *
     * If you have Tesseract installed locally, executing `tesseract --print-parameters`
     * will also display a list of configuration variables.
     */
    setParameters(parameters: Record<string, string>): Promise<void>;
}