import { DocumentSource } from '../types';
export interface ThumbnailOptions {
    width?: number;
    height?: number;
    quality?: number;
}
export declare class ThumbnailGenerator {
    private cache;
    /**
     * Generate thumbnail for a document
     */
    generateThumbnail(document: DocumentSource, options?: ThumbnailOptions): Promise<string | null>;
    /**
     * Generate thumbnail for PDF (first page)
     */
    private generatePDFThumbnail;
    /**
     * Generate thumbnail for images
     */
    private generateImageThumbnail;
    /**
     * Clear thumbnail cache
     */
    clearCache(): void;
    /**
     * Get file extension from URI
     */
    private getFileExtension;
}
export declare const thumbnailGenerator: ThumbnailGenerator;
//# sourceMappingURL=thumbnailGenerator.d.ts.map