@syncfusion/ej2-pdf
Version:
Feature-rich JavaScript PDF library with built-in support for loading and manipulating PDF document.
98 lines (97 loc) • 3.03 kB
TypeScript
import { _ImageDecoder } from './image-decoder';
import { _PdfStream } from './../../base-stream';
import { _PdfDictionary } from './../../pdf-primitives';
export declare class _PngDecoder extends _ImageDecoder {
_isRedGreenBlue: boolean;
_shades: boolean;
_ideateDecode: boolean;
_colors: number;
_bitsPerPixel: number;
_idatLength: number;
_inputBands: number;
_isDecode: boolean;
_currentChunkLength: number;
_header: _PngHeader;
_encodedStream: number[];
_maskData: number[];
_colorSpace: any[];
_alpha: number[];
_dataStream: number[];
_decodedImageData: number[];
_dataStreamOffset: number;
/**
* Initializes a new instance of the `_PngDecoder` class.
*
* @private
* @param {Uint8Array} stream byte array.
*/
constructor(stream: Uint8Array);
_initialize(): void;
_hasValidChunkType(type: _PngChunkTypes): {
type: _PngChunkTypes;
hasValidChunk: boolean;
};
_ignoreChunk(): void;
_readHeader(): void;
_setBitsPerPixel(): void;
_readImageData(): void;
_readPhotoPlate(): void;
_readTransparency(): void;
_getPngColorSpace(): any;
_decodeImageData(): void;
_getDeflatedData(data: number[]): number[];
_readDecodeData(): void;
_decodeData(xOffset: number, yOffset: number, xStep: number, yStep: number, width: number, height: number): void;
_readStream(stream: number[], streamOffset: number, data: number[], count: number): number;
_decompressSub(data: number[], count: number, bitsPerPixel: number): void;
_decompressUp(data: number[], pData: number[], count: number): void;
_decompressAverage(data: number[], pData: number[], count: number, bitsPerPixel: number): void;
_decompressPaeth(data: number[], pData: number[], count: number, bitsPerPixel: number): void;
_paethPredictor(a: number, b: number, c: number): number;
_processPixels(data: number[], x: number, step: number, y: number, width: number): void;
_getPixel(data: number[]): number[];
_setPixel(imageData: number[], data: number[], offset: number, size: number, x: number, y: number, bitDepth: number, bpr: number): number[];
_getImageDictionary(): _PdfStream;
_setMask(): void;
_getDecodeParams(): _PdfDictionary;
_getChunkType(chunk: string): _PngChunkTypes;
_getFilterType(type: number): _PngFilterTypes;
}
declare class _PngHeader {
constructor();
_width: number;
_height: number;
_colorType: number;
_compression: number;
_bitDepth: number;
_filter: _PngFilterTypes;
_interlace: number;
}
declare enum _PngChunkTypes {
iHDR = 0,
pLTE = 1,
iDAT = 2,
iEND = 3,
bKGD = 4,
cHRM = 5,
gAMA = 6,
hIST = 7,
pHYs = 8,
sBIT = 9,
tEXt = 10,
tIME = 11,
tRNS = 12,
zTXt = 13,
sRGB = 14,
iCCP = 15,
iTXt = 16,
unknown = 17
}
declare enum _PngFilterTypes {
none = 0,
sub = 1,
up = 2,
average = 3,
paeth = 4
}
export {};