/**
 * PDF metadata reader.
 *
 * Extracts document metadata from:
 * 1. Info Dictionary (traditional metadata)
 *    - Title, Author, Subject, Keywords, Creator, Producer
 *    - CreationDate, ModDate
 *
 * 2. XMP Metadata Stream (XML-based, more comprehensive)
 *    - All of the above plus:
 *    - Dublin Core metadata, custom properties
 *
 * @see PDF Reference 1.7, §10.2 - Metadata
 * @see XMP Specification Part 1
 */
import type { PdfDocument } from "./pdf-document.js";
/**
 * PDF document metadata.
 */
export interface PdfMetadata {
    /** Document title */
    title: string;
    /** Document author */
    author: string;
    /** Document subject */
    subject: string;
    /** Document keywords */
    keywords: string;
    /** Application that created the original document */
    creator: string;
    /** Application that produced the PDF */
    producer: string;
    /** Date the document was created */
    creationDate: Date | null;
    /** Date the document was last modified */
    modDate: Date | null;
    /** PDF version */
    pdfVersion: string;
    /** Number of pages */
    pageCount: number;
    /** Whether the document is encrypted */
    encrypted: boolean;
    /** Page size of the first page (in points) */
    pageSize: {
        width: number;
        height: number;
    } | null;
    /** Raw XMP metadata XML (if available) */
    xmpXml: string | null;
    /** Additional custom metadata from Info dictionary */
    custom: Record<string, string>;
}
/**
 * Extract metadata from a PDF document.
 */
export declare function extractMetadata(doc: PdfDocument): PdfMetadata;