@syncfusion/ej2-pdf/src/pdf/core/graphics/images/jbig2-image.d.ts

Feature-rich JavaScript PDF library with built-in support for loading and manipulating PDF document.

/**
 * Helper that reads a specified number of bits using the arithmetic decoder,
 * maintaining a rolling context state for JBIG2 procedures.
 *
 * @private
 */
export declare class _PdfBitReader {
    private prev;
    /**
     * Reads `length` bits using the arithmetic decoder with the provided contexts,
     * updating the internal rolling context (`prev`) and returning the accumulated value.
     *
     * @private
     * @param {number} length The number of bits to read.
     * @param {any} decoder The arithmetic decoder supplying `_readBit(contexts, state)`.
     * @param {any} contexts The JBIG2 context states used by the decoder.
     * @returns {number} The unsigned integer composed from the read bits.
     */
    _readBits(length: number, decoder: any, contexts: any): number;
}
/**
 * Caches and supplies JBIG2 context state arrays (lazily initialized),
 * keyed by a procedure or identifier.
 *
 * @private
 */
export declare class _PdfContextCache {
    private cache;
    getContexts(id: string | number): Int8Array;
}
/**
 * Holds the decoding window over the input data and lazily exposes
 * the arithmetic decoder and the shared JBIG2 context cache.
 *
 * @private
 */
export declare class _PdfDecodingContext {
    /**
     * Backing data buffer to decode from.
     *
     * @private
     */
    _data: Uint8Array;
    /**
     * Start offset within the data buffer.
     *
     * @private
     */
    _start: number;
    /**
     * End offset within the data buffer.
     *
     * @private
     */
    _end: number;
    constructor(data: Uint8Array, start: number, end: number);
    readonly decoder: any;
    readonly contextCache: any;
}
/**
 * Segment visitor that decodes JBIG2 segments generic/text/halftone/symbol tables,
 * manages symbol/pattern/table caches, and composites bitmaps into the page buffer.
 *
 * @private
 */
export declare class _PdfSimpleSegmentVisitor {
    /**
     * Holds per-page decoding metadata and parameters.
     *
     * @private
     */
    _currentPageInfo: any;
    /**
     * Destination pixel buffer used during composition.
     *
     * @private
     */
    _buffer: Uint8ClampedArray;
    /**
     * Custom decoding tables supplied by the stream or caller.
     *
     * @private
     */
    _customTables: any;
    /**
     * Symbol dictionary used for JBIG2 text/region decoding.
     *
     * @private
     */
    _symbols: any;
    /**
     * Pattern dictionary used for halftone/region reconstruction.
     *
     * @private
     */
    _patterns: any;
    /**
     * Cache of standard Huffman tables keyed by table id.
     *
     * @private
     */
    _standardTablesCache: {
        [key: number]: _PdfHuffmanTable;
    };
    /**
     * Neighborhood coding templates for generic regions.
     *
     * @private
     */
    _codingTemplates: {
        x: number;
        y: number;
    }[][];
    /**
     * Refinement region coding and reference templates.
     *
     * @private
     */
    _refinementTemplates: {
        coding: {
            x: number;
            y: number;
        }[];
        reference: {
            x: number;
            y: number;
        }[];
    }[];
    /**
     * Context states reused for generic region decoding.
     *
     * @private
     */
    _reusedContexts: number[];
    /**
     * Context states reused for refinement region decoding.
     *
     * @private
     */
    _refinementReusedContexts: number[];
    /**
     * Initializes page-level state from the `PageInformation` segment and allocates
     * the destination bit buffer (row-major, bit-packed).
     *
     * @private
     * @param {any} info The page information array (first entry contains width/height and flags).
     * @returns {void}
     */
    _onPageInformation(info: any): void;
    /**
     * Composites a decoded bitmap into the page buffer using the specified
     * combination operator at the region position.
     *
     * @private
     * @param {any} regionInfo The region info with `x`, `y`, `width`, `height`.
     * @param {any} bitmap The 2D bitmap array (rows of 0/1) to draw.
     * @returns {void}
     */
    _drawBitmap(regionInfo: any, bitmap: any): void;
    /**
     * Decodes and draws an Immediate Generic Region segment.
     *
     * @private
     * @param {any} region The parsed region descriptor.
     * @param {Uint8Array} data The segment data buffer.
     * @param {number} start The start offset within `data`.
     * @param {number} end The end offset within `data`.
     * @returns {void}
     */
    _onImmediateGenericRegion(region: any, data: Uint8Array, start: number, end: number): void;
    /**
     * Resolves a custom Huffman table by index among the referred segments/custom tables.
     *
     * @private
     * @param {number} index The zero-based custom table index to retrieve.
     * @param {number[]} referredTo The list of referred segment numbers.
     * @param {any} customTables The dictionary of custom tables by segment id.
     * @returns {any} The matching custom Huffman table.
     */
    _getCustomHuffmanTable(index: number, referredTo: number[], customTables: any): any;
    /**
     * Builds all Huffman tables required for a Huffman-coded text region:
     * symbol ID table and delta tables (S/DS/DT).
     *
     * @private
     * @param {any} textRegion The text region parameters.
     * @param {any} referredTo Referred segment ids.
     * @param {any} customTables Custom Huffman tables dictionary.
     * @param {number} numberOfSymbols Total symbols available for coding.
     * @param {_PdfReader} reader The bit reader used to decode table definitions.
     * @returns {any} An object containing `symbolIDTable`, `tableFirstS`, `tableDeltaS`, `tableDeltaT`.
     */
    _getTextRegionHuffmanTables(textRegion: any, //eslint-disable-line
    referredTo: any, //eslint-disable-line
    customTables: any, //eslint-disable-line
    numberOfSymbols: number, reader: _PdfReader): any;
    /**
     * Returns a predefined (standard) Huffman table by its B.n number, caching it for reuse.
     *
     * @private
     * @param {number} number The standard table identifier (B.1..B.15 etc.).
     * @returns {_PdfHuffmanTable} The standard Huffman table instance.
     */
    _getStandardTable(number: number): _PdfHuffmanTable;
    /**
     * Prepares Huffman tables for symbol dictionary decoding: delta height/width, bitmap size,
     * and aggregate instances, resolving from standard or custom tables.
     *
     * @private
     * @param {{huffmanDHSelector:number, huffmanDWSelector:number, bitmapSizeSelector:boolean, aggregationInstancesSelector:boolean}} dictionary The dictionary flags/selectors.
     * @param {any} referredTo Referred segment ids.
     * @param {any} customTables Custom Huffman tables dictionary.
     * @returns {{tableDeltaHeight:number, tableDeltaWidth:number, tableBitmapSize:number, tableAggregateInstances:any}} The required Huffman tables.
     */
    _getSymbolDictionaryHuffmanTables(dictionary: {
        huffmanDHSelector: number;
        huffmanDWSelector: number;
        bitmapSizeSelector: boolean;
        aggregationInstancesSelector: boolean;
    }, referredTo: any, customTables: any): {
        tableDeltaHeight: number;
        tableDeltaWidth: number;
        tableBitmapSize: number;
        tableAggregateInstances: any;
    };
    /**
     * Reads a raw (uncompressed) bitmap from the bit stream into a 2D array.
     *
     * @private
     * @param {any} reader The bit reader providing `_readBit()` and `byteAlign()`.
     * @param {number} width The bitmap width in pixels.
     * @param {number} height The bitmap height in pixels.
     * @returns {Uint8Array[]} The decoded bitmap (rows of 0/1 values).
     */
    _readUncompressedBitmap(reader: any, width: number, height: number): Uint8Array[];
    /**
     * Decodes an MMR (fax) compressed bitmap into a 2D array of bits.
     *
     * @private
     * @param {any} input The input providing `readNextChar()` bytes.
     * @param {number} width The bitmap width in pixels.
     * @param {number} height The bitmap height in pixels.
     * @param {boolean} endOfBlock Whether to consume an end-of-block marker.
     * @returns {Uint8Array[]} The decoded bitmap (rows of 0/1 values).
     */
    _decodeMmrBitmap(input: any, width: number, height: number, endOfBlock: boolean): Uint8Array[];
    /**
     * Decodes a Symbol Dictionary segment and stores the resulting symbol bitmaps
     * keyed by the current segment id.
     *
     * @private
     * @param {any} dictionary The symbol dictionary parameters.
     * @param {any} currentSegment The current segment number.
     * @param {any} referredSegments The list of referred segment ids.
     * @param {Uint8Array} data The data buffer.
     * @param {number} start Start offset.
     * @param {number} end End offset.
     * @returns {void}
     */
    _onSymbolDictionary(dictionary: any, currentSegment: any, referredSegments: any, // eslint-disable-line
    data: Uint8Array, start: number, end: number): void;
    /**
     * Decodes and draws an Immediate Text Region (optionally Huffman-coded),
     * composing the decoded symbols into the page bitmap.
     *
     * @private
     * @param {any} region The text region parameters.
     * @param {string[]} referredSegments Referred segment ids (as strings).
     * @param {Uint8Array} data The data buffer.
     * @param {number} start Start offset.
     * @param {number} end End offset.
     * @returns {void}
     */
    _onImmediateTextRegion(region: any, referredSegments: string[], data: Uint8Array, start: number, end: number): void;
    /**
     * Decodes a Pattern Dictionary segment and stores patterns by segment id.
     *
     * @private
     * @param {any} dictionary The pattern dictionary parameters.
     * @param {string} currentSegment The current segment number.
     * @param {Uint8Array} data The data buffer.
     * @param {number} start Start offset.
     * @param {number} end End offset.
     * @returns {void}
     */
    _onPatternDictionary(dictionary: any, currentSegment: string, data: Uint8Array, start: number, end: number): void;
    /**
     * Decodes and draws an Immediate Halftone Region using previously decoded patterns.
     *
     * @private
     * @param {any} region The halftone region parameters.
     * @param {string[]} referredSegments Ids referencing the pattern dictionary.
     * @param {Uint8Array} data The data buffer.
     * @param {number} start Start offset.
     * @param {number} end End offset.
     * @returns {void}
     */
    _onImmediateHalftoneRegion(region: any, referredSegments: string[], data: Uint8Array, start: number, end: number): void;
    /**
     * Decodes a Tables segment and caches the resulting custom Huffman tables under the segment id.
     *
     * @private
     * @param {string} currentSegment The current segment number.
     * @param {Uint8Array} data The data buffer.
     * @param {number} start Start offset in `data`.
     * @param {number} end End offset in `data`.
     * @returns {void}
     */
    _onTables(currentSegment: string, data: Uint8Array, start: number, end: number): void;
    /**
     * Decodes a custom Huffman table from a Tables segment payload.
     *
     * @private
     * @param {Uint8Array} data The data buffer.
     * @param {number} start Start offset in `data`.
     * @param {number} end End offset in `data`.
     * @returns {_PdfHuffmanTable} The constructed custom Huffman table.
     */
    _decodeTablesSegment(data: Uint8Array, start: number, end: number): _PdfHuffmanTable;
    /**
     * Fast-path decoding for Generic Region template 0 with default AT positions,
     * producing a bitmap using the specified arithmetic decoder contexts.
     *
     * @private
     * @param {number} width Bitmap width in pixels.
     * @param {number} height Bitmap height in pixels.
     * @param {_PdfDecodingContext} decodingContext The decoding context providing decoder and contexts.
     * @returns {Uint8Array[]} The decoded bitmap.
     */
    _decodeBitmapTemplate0(width: number, height: number, decodingContext: _PdfDecodingContext): Uint8Array[];
    /**
     * Decodes a Generic Region bitmap (MMR or arithmetic-coded) with the specified template,
     * prediction mode, optional skip mask, and AT positions.
     *
     * @private
     * @param {boolean} mmr Whether the bitmap is MMR-compressed.
     * @param {number} width Bitmap width.
     * @param {number} height Bitmap height.
     * @param {number} templateIndex JBIG2 template index (0..3).
     * @param {boolean} prediction When true, uses LTP prediction.
     * @param {boolean[][]} skip Optional skip mask (true = skip decoding at pixel).
     * @param {{x:number, y:number}[]} at Additional relative AT positions.
     * @param {_PdfDecodingContext} decodingContext The decoding context.
     * @returns {Uint8Array[]} The decoded bitmap.
     */
    _decodeBitmap(mmr: boolean, width: number, height: number, templateIndex: number, prediction: boolean, skip: boolean[][], at: {
        x: number;
        y: number;
    }[], decodingContext: _PdfDecodingContext): Uint8Array[];
    /**
     * Decodes a Refinement Region bitmap using coding and reference templates applied
     * against a reference bitmap with given offsets.
     *
     * @private
     * @param {number} width Output width.
     * @param {number} height Output height.
     * @param {number} templateIndex Refinement template index (0/1).
     * @param {any} referenceBitmap The reference bitmap (2D 0/1).
     * @param {number} offsetX X offset into the reference.
     * @param {number} offsetY Y offset into the reference.
     * @param {any} prediction Prediction flag (unused/unsupported when true).
     * @param {any} at Additional AT positions.
     * @param {_PdfDecodingContext} decodingContext The decoding context.
     * @returns {Uint8Array[]} The decoded refinement bitmap.
     */
    _decodeRefinement(width: number, height: number, templateIndex: number, referenceBitmap: any, // eslint-disable-line
    offsetX: number, offsetY: number, prediction: any, at: any, decodingContext: _PdfDecodingContext): Uint8Array[];
    /**
     * Decodes a Symbol Dictionary, producing and (optionally) exporting symbol bitmaps
     * using either arithmetic or Huffman coding with optional refinement.
     *
     * @private
     * @param {any} huffman Whether Huffman coding is used.
     * @param {any} refinement Whether refinement coding is used.
     * @param {any} symbols Existing input symbol bitmaps.
     * @param {number} numberOfNewSymbols Number of new symbols to decode.
     * @param {number} numberOfExportedSymbols Number of symbols to export.
     * @param {any} huffmanTables Huffman tables bundle when `huffman` is true.
     * @param {number} templateIndex Generic Region template for symbol bitmaps.
     * @param {{x:number,y:number}[]} at AT positions for generic template.
     * @param {number} refinementTemplateIndex Refinement template index.
     * @param {any} refinementAt AT positions for refinement.
     * @param {_PdfDecodingContext} decodingContext The decoding context.
     * @param {any} huffmanInput The Huffman bit reader when `huffman` is true.
     * @returns {any[]} The exported symbol bitmaps.
     */
    _decodeSymbolDictionary(huffman: any, refinement: any, symbols: any, numberOfNewSymbols: number, // eslint-disable-line
    numberOfExportedSymbols: number, huffmanTables: any, templateIndex: number, // eslint-disable-line
    at: {
        x: number;
        y: number;
    }[], refinementTemplateIndex: number, refinementAt: any, // eslint-disable-line
    decodingContext: _PdfDecodingContext, huffmanInput: any): any[];
    /**
     * Decodes a signed integer using the specified JBIG2 integer procedure contexts.
     *
     * @private
     * @param {any} contextCache The context cache providing states by procedure name.
     * @param {any} procedure The procedure id/name (e.g., 'IADW', 'IADT', 'IAID').
     * @param {any} decoder The arithmetic decoder.
     * @returns {number} The decoded signed integer (32-bit range).
     */
    _decodeInteger(contextCache: any, procedure: any, decoder: any): number;
    /**
     * Decodes an unsigned integer of the given bit-length using the IAID procedure.
     *
     * @private
     * @param {any} contextCache The context cache.
     * @param {any} decoder The arithmetic decoder.
     * @param {any} codeLength The number of bits to decode.
     * @returns {number} The decoded unsigned value.
     */
    _decodeImageData(contextCache: any, decoder: any, codeLength: any): number;
    /**
     * Decodes a Text Region by placing symbol bitmaps (with optional refinement)
     * onto a target bitmap using the specified combination operator.
     *
     * @private
     * @param {any} huffman Whether Huffman coding is used.
     * @param {any} refinement Whether refinement coding is used.
     * @param {number} width Region width.
     * @param {number} height Region height.
     * @param {any} defaultPixelValue Initial fill value for the region rows (0/1).
     * @param {any} numberOfSymbolInstances Number of symbol placements.
     * @param {any} stripSize The strip height.
     * @param {any} inputSymbols The list of available symbol bitmaps.
     * @param {any} symbolCodeLength Bit-length for symbol ids (IAID).
     * @param {any} transposed Whether symbols are laid out transposed.
     * @param {any} dsOffset Delta-S offset.
     * @param {any} referenceCorner Reference corner selector.
     * @param {any} combinationOperator Composition operator (e.g., 0 = OR, 2 = XOR).
     * @param {any} huffmanTables Huffman tables bundle when `huffman` is true.
     * @param {any} refinementTemplateIndex Refinement template index.
     * @param {any} refinementAt AT positions for refinement.
     * @param {any} decodingContext The decoding context.
     * @param {any} logStripSize Log2 of strip size (when Huffman-coded).
     * @param {any} huffmanInput The Huffman input reader when `huffman` is true.
     * @returns {any} The decoded text region bitmap (2D array).
     */
    _decodeTextRegion(huffman: any, refinement: any, width: number, height: number, defaultPixelValue: any, // eslint-disable-line
    numberOfSymbolInstances: any, stripSize: any, inputSymbols: any, symbolCodeLength: any, // eslint-disable-line
    transposed: any, dsOffset: any, referenceCorner: any, combinationOperator: any, huffmanTables: any, // eslint-disable-line
    refinementTemplateIndex: any, refinementAt: any, decodingContext: any, logStripSize: any, // eslint-disable-line
    huffmanInput: any): any;
    /**
     * Decodes a Pattern Dictionary into an array of pattern bitmaps by slicing a collective bitmap.
     *
     * @private
     * @param {any} mmr Whether MMR compression is used.
     * @param {number} patternWidth Pattern tile width.
     * @param {number} patternHeight Pattern tile height.
     * @param {any} maxPatternIndex Maximum pattern index (inclusive).
     * @param {any} template Generic Region template index.
     * @param {any} decodingContext The decoding context.
     * @returns {any} An array of pattern bitmaps (2D arrays).
     */
    _decodePatternDictionary(mmr: any, patternWidth: number, patternHeight: number, maxPatternIndex: any, // eslint-disable-line
    template: any, decodingContext: any): any;
    /**
     * Decodes a Halftone Region by assembling patterns based on gray-scale bit planes
     * and placing them onto the target bitmap using the specified grid.
     *
     * @private
     * @param {any} mmr Whether bit planes are MMR-compressed.
     * @param {any} patterns The pattern dictionary (array of bitmaps).
     * @param {any} template Generic Region template index for bit planes.
     * @param {any} regionWidth Region width.
     * @param {any} regionHeight Region height.
     * @param {any} defaultPixelValue Initial row fill value (0/1).
     * @param {any} enableSkip Whether skip is enabled (unsupported here).
     * @param {any} combinationOperator Composition operator (0 = OR required).
     * @param {number} gridWidth Grid width in cells.
     * @param {number} gridHeight Grid height in cells.
     * @param {number} gridOffsetX Fixed-point X offset (8.8).
     * @param {number} gridOffsetY Fixed-point Y offset (8.8).
     * @param {number} gridVectorX Fixed-point X vector (8.8).
     * @param {any} gridVectorY Fixed-point Y vector (8.8).
     * @param {any} decodingContext The decoding context.
     * @returns {any} The decoded halftone region bitmap (2D array).
     */
    _decodeHalftoneRegion(mmr: any, patterns: any, template: any, regionWidth: any, regionHeight: any, // eslint-disable-line
    defaultPixelValue: any, enableSkip: any, combinationOperator: any, gridWidth: number, // eslint-disable-line
    gridHeight: number, gridOffsetX: number, gridOffsetY: number, gridVectorX: number, gridVectorY: any, decodingContext: any): any;
}
/**
 * Represents a single Huffman table entry, including range bounds,
 * prefix length/code, and flags.
 *
 * @private
 */
export declare class _PdfHuffmanLine {
    isoob: boolean;
    rangeLow: number;
    prefixLength: number;
    rangeLength: number;
    prefixCode: number;
    isLowerRange: boolean;
    constructor(lineData: any);
}
/**
 * Node in a Huffman decoding tree that can be extended from prefix codes
 * and used to decode values from a bit reader.
 *
 * @private
 */
export declare class _PdfHuffmanTreeNode {
    children: _PdfHuffmanTreeNode[];
    isLeaf: boolean;
    rangeLength: number;
    rangeLow: number;
    isLowerRange: boolean;
    isoob: boolean;
    constructor(line: _PdfHuffmanLine);
    /**
     * Inserts a Huffman line into the decoding tree according to its prefix code.
     *
     * @private
     * @param {_PdfHuffmanLine} line The Huffman line defining a code range or OOB.
     * @param {number} shift The remaining bit shift (prefixLength - 1 .. 0).
     * @returns {void}
     */
    _buildTree(line: _PdfHuffmanLine, shift: number): void;
    /**
     * Decodes a value  by traversing the tree using bits from the reader,
     * and applies the range adjustment when needed.
     *
     * @private
     * @param {any} reader The reader exposing `_readBit()` / `_readBits(n)`.
     * @returns {number | null} The decoded value, or `null` if OOB was reached.
     */
    _decodeNode(reader: any): number | null;
}
/**
 * Canonical Huffman table that assigns prefix codes to lines, builds a decode tree,
 * and provides value decoding against a bit reader.
 *
 * @private
 */
export declare class _PdfHuffmanTable {
    rootNode: _PdfHuffmanTreeNode;
    constructor(lines: _PdfHuffmanLine[], prefixCodesDone: boolean);
    decode(reader: any): number | null;
    assignPrefixCodes(lines: _PdfHuffmanLine[]): void;
}
/**
 * MSB first bit reader over a byte array for Huffman/bit level parsing,
 * with byte alignment support.
 *
 * @private
 */
export declare class _PdfReader {
    data: Uint8Array;
    start: number;
    end: number;
    position: number;
    shift: number;
    currentByte: number;
    constructor(data: Uint8Array, start: number, end: number);
    /**
     * Reads a single bit from the underlying byte stream, refilling as needed.
     *
     * @private
     * @returns {number} The next bit (0 or 1).
     * @throws {Error} If the end of input is reached prematurely.
     */
    _readBit(): number;
    /**
     * Reads `numBits` bits MSB-first and returns the aggregated value.
     *
     * @private
     * @param {number} numBits The number of bits to read.
     * @returns {number} The unsigned integer composed from the read bits.
     */
    _readBits(numBits: number): number;
    byteAlign(): void;
    next(): number;
}
/**
 * JBIG2 image parser that reads headers and segments, dispatches work to the visitor,
 * and produces unpacked image data.
 *
 * @private
 */
export declare class _PdfJbig2Image {
    width: number;
    height: number;
    /**
     * Field length of the region segment information.
     *
     * @private
     */
    _regionSegmentInformationFieldLength: number;
    /**
     * Lookup of segment type names by id.
     *
     * @private
     */
    _segmentTypes: (string | null)[];
    /**
     * Parses a sequence of JBIG2 chunks and returns the bit-packed page buffer.
     *
     * @private
     * @param {any} chunks The array of chunk objects containing `data`, `start`, and `end`.
     * @returns {any} The bit-packed image buffer of the last processed page.
     */
    _parseChunks(chunks: any): any;
    /**
     * Parses a complete JBIG2 stream and returns the unpacked 8-bit grayscale image data.
     *
     * @private
     * @param {any} data The input JBIG2 byte array.
     * @returns {any} The unpacked image data buffer.
     */
    _parse(data: any): any;
    /**
     * Processes a list of segments by dispatching each to the segment visitor.
     *
     * @private
     * @param {any} segments The parsed JBIG2 segments.
     * @param {_PdfSimpleSegmentVisitor} visitor The visitor handling segment types.
     * @returns {any} as process segment.
     */
    _processSegments(segments: any, visitor: _PdfSimpleSegmentVisitor): any;
    /**
     * Parses an entire JBIG2 file/stream (with header), processes segments, and
     * converts the bit-packed page buffer to 8-bit grayscale image data.
     *
     * @private
     * @param {Uint8Array} data The full JBIG2 data.
     * @returns {{imgData: Uint8ClampedArray, width: number, height: number}} Decoded image buffer and dimensions.
     */
    _parseJbig2(data: Uint8Array): {
        imgData: Uint8ClampedArray;
        width: number;
        height: number;
    };
    /**
     * Parses and processes JBIG2 segments from chunked inputs (e.g., inline images),
     * returning the bit-packed page buffer.
     *
     * @private
     * @param {any} chunks The chunk array with `data`, `start`, and `end`.
     * @returns {any} The bit-packed image buffer.
     */
    _parseJbig2Chunks(chunks: any): any;
    /**
     * Reads a segment header starting at `start`, validating type, extracting flags,
     * referred-to segments, page association, and length.
     *
     * @private
     * @param {Uint8Array} data The data buffer.
     * @param {number} start The start offset of the header.
     * @returns {{number:number, type:number, typeName:string|null, deferredNonRetain:boolean, retainBits:number[], pageAssociation:number, length:number, referredTo:number[], headerEnd:number}} The parsed header structure.
     */
    _readSegmentHeader(data: Uint8Array, start: number): {
        number: number;
        type: number;
        typeName: string | null;
        deferredNonRetain: boolean;
        retainBits: number[];
        pageAssociation: number;
        length: number;
        referredTo: number[];
        headerEnd: number;
    };
    /**
     * Iterates the stream to collect segments  until EOF or EndOfFile segment.
     *
     * @private
     * @param {any} header The file header (randomAccess/numberOfPages).
     * @param {any} data The data buffer.
     * @param {number} start Start offset.
     * @param {number} end End offset.
     * @returns {any} The list of segments with parsed headers and data ranges.
     */
    _readSegments(header: any, data: any, start: number, end: number): any;
    /**
     * Dispatches a single segment to the appropriate visitor callback based on its type,
     * parsing type-specific payload arguments beforehand.
     *
     * @private
     * @param {{header:{type:number, number:number, referredTo:number}, data:Uint8Array, start:number, end:number}} segment The segment to process. // eslint-disable-line
     * @param {any} visitor The segment visitor instance.
     * @returns {void}
     */
    _processSegment(segment: {
        header: {
            type: number;
            number: number;
            referredTo: number;
        };
        data: Uint8Array;
        start: number;
        end: number;
    }, visitor: any): void;
    /**
     * Reads a `RegionSegmentInformation` structure (width, height, position, operator).
     *
     * @private
     * @param {Uint8Array} data The data buffer.
     * @param {number} start Start offset of the structure.
     * @returns {{width:number, height:number, x:number, y:number, combinationOperator:number}} The parsed region information.
     */
    _readRegionSegmentInformation(data: Uint8Array, start: number): {
        width: number;
        height: number;
        x: number;
        y: number;
        combinationOperator: number;
    };
}