export declare const LANG_PATTERN: RegExp;
export interface OcrRequest {
    readonly path: string;
    readonly lang: string;
    readonly psmCandidates: readonly number[];
    readonly timeoutMs: number;
    readonly dpi?: number | undefined;
    readonly preprocess?: boolean | undefined;
    readonly signal?: AbortSignal | undefined;
    readonly onOutput?: ((chunk: string, stream: "stdout" | "stderr") => void) | undefined;
}
export interface OcrResult {
    readonly ok: boolean;
    readonly text: string;
    readonly psm: number;
    readonly preprocessed: boolean;
    readonly confidence: number;
    readonly reliable: boolean;
    readonly error?: string | undefined;
}
export declare const MIN_RELIABLE_CONFIDENCE = 55;
export declare function stripCommandEcho(output: string): string;
export declare function meaningfulCharCount(text: string): number;
export declare function scoreOcrText(text: string): number;
export declare function tesseractUnavailableReason(): Promise<string | undefined>;
export declare function languageUnavailableReason(lang: string): Promise<string | undefined>;
export declare function resetOcrEnvironmentCache(): void;
export declare function runOcr(request: OcrRequest): Promise<OcrResult>;