declare const VALID_RESOLUTIONS: readonly ["screen", "ebook", "printer", "prepress", "default"];
type Resolution = (typeof VALID_RESOLUTIONS)[number];
type Options = {
    compatibilityLevel?: number;
    /**
     * Can be
     *
     * `screen` selects low-resolution output similar to the Acrobat Distiller (up to version X) "Screen Optimized" setting.
     *
     * `ebook` selects medium-resolution output similar to the Acrobat Distiller (up to version X) "eBook" setting.
     *
     * `printer` selects output similar to the Acrobat Distiller "Print Optimized" (up to version X) setting.
     *
     * `prepress` selects output similar to Acrobat Distiller "Prepress Optimized" (up to version X) setting.
     *
     * `default` selects output intended to be useful across a wide variety of uses, possibly at the expense of a larger output file.
     *
     * Default is `ebook`
     */
    resolution?: Resolution;
    /**
     * Set quality of pdf images (DPI).
     * Must be between 1 and 600.
     * Default is `100`
     */
    imageQuality?: number;
    /**
     * The path for ghostscript binary directory.
     *
     * `You can download binaries in releases section inside any version of this repository.`
     */
    gsModule?: string;
    /**
     * The pdf password
     */
    pdfPassword?: string;
    /**
     * Remove password of a protected pdf, after compression
     */
    removePasswordAfterCompression?: boolean;
};
/**
 * Result of a PDF compression operation.
 */
type CompressResult = {
    /** The compressed PDF as a Buffer */
    buffer: Buffer;
    /** Original file size in bytes */
    originalSize: number;
    /** Compressed file size in bytes */
    compressedSize: number;
    /** Compression ratio (e.g., 0.65 means 35% smaller) */
    compressionRatio: number;
    /** Time taken in milliseconds */
    duration: number;
};
/**
 * Custom error class for compress-pdf errors.
 */
declare class CompressPdfError extends Error {
    readonly cause?: unknown | undefined;
    constructor(message: string, cause?: unknown | undefined);
}

export { CompressPdfError, type CompressResult, type Options, type Resolution, VALID_RESOLUTIONS };