/**
 * PDF resource dictionary merger — structured merging at the parsed object level.
 *
 * Instead of manipulating serialized PDF dict strings directly, this module
 * parses resource dicts into a structured `PdfResourceDict` (nested Maps),
 * merges them, and serializes back to PDF dict strings.
 */
/**
 * Structured representation of a PDF resource dictionary.
 *
 * Outer key: category name (e.g. `Font`, `XObject`, `ExtGState`, `ColorSpace`,
 * `Pattern`, `Shading`, `Properties`).
 * Inner key: resource name (e.g. `F1`, `Im1`, `GS0`).
 * Value: serialized ref or value string (e.g. `3 0 R`, `/DeviceRGB`).
 *
 * Categories whose value is not a sub-dict (e.g. `/ProcSet [/PDF /Text]`)
 * are stored with an empty inner key `""` mapping to the raw value string.
 */
export type PdfResourceDict = Map<string, Map<string, string>>;
/**
 * Merge two parsed resource dicts. For sub-dict categories, entries are
 * combined; overlay entries win on name collision. For non-sub-dict categories,
 * the overlay value replaces the original.
 */
export declare function mergeResourceDicts(original: PdfResourceDict, overlay: PdfResourceDict): PdfResourceDict;
/**
 * Parse a serialized PDF resource dict string into a structured `PdfResourceDict`.
 *
 * Handles top-level entries like:
 * ```
 * << /Font << /F1 3 0 R /F2 5 0 R >> /XObject << /Im1 7 0 R >> /ProcSet [/PDF /Text] >>
 * ```
 *
 * Sub-dict categories (`Font`, `XObject`, etc.) are parsed into inner name→value maps.
 * Other categories are stored with a single entry keyed by `""`.
 */
export declare function parseResourceDict(dictStr: string): PdfResourceDict;
/**
 * Serialize a structured `PdfResourceDict` back to a PDF dict string.
 */
export declare function serializeResourceDict(dict: PdfResourceDict): string;