Class Lzw in namespace setasign\SetaPDF2\Core\Image\Gif\Filter in SetaPDF v2 API Reference

Index

\setasign\SetaPDF2
1. Core
  1. Image
    1. Gif
    2. Gif
      1. Filter
        
        Interlace
        
        Lzw

setasign\SetaPDF2\Core\Image\Gif\Filter

Lzw Class to apply LZW encoding.

File: /SetaPDF v2/Core/Image/Gif/Filter/Lzw.php
Old class name (alias): \SetaPDF_Core_Image_Gif_Filter_Lzw

Class hierarchy

Summary

Properties

$_clearCode
$_codeSize
$_endCode
$_initialCodeSize
$_nextCode
$_nextCodeLimit
$_outputBuffer
$_reader
$_table

Properties

$_clearCode

private int Lzw::$_clearCode

The clear code.

This code marks a reset of the LZW stream.

$_codeSize

private int Lzw::$_codeSize

The code size.

This value marks the current size of codes.

$_endCode

private int Lzw::$_endCode

The end code.

This code marks the end of the LZW stream.

$_initialCodeSize

private int Lzw::$_initialCodeSize

The initial code size.

The value marks the code size before running the LZW algorithm.

$_nextCode

private int Lzw::$_nextCode

The next code. This code marks the next unassigned code.

$_nextCodeLimit

private int Lzw::$_nextCodeLimit

A value that marks a limit to increase the bit size.

$_outputBuffer

private array Lzw::$_outputBuffer

The output buffer.

$_reader

private \SetaPDF_Core_Image_Gif_Reader_Bit Lzw::$_reader

The currently used reader instance.

$_table

private array Lzw::$_table

The code table.

Methods

__construct()

public Lzw::__construct (

\SetaPDF_Core_Image_Gif_Reader_Bit $reader,
int $minimumCodeSize,
array $colorTable

)

The constructor.

Parameters

$reader : \SetaPDF_Core_Image_Gif_Reader_Bit
$minimumCodeSize : int
$colorTable : array

_clearAndOutput()

protected Lzw::_clearAndOutput (

void

): int

Resets the LZW code-table, reads away all the clear codes and outputs the first given code.

Exceptions

Throws \setasign\SetaPDF2\Core\Image\Exception

_output()

protected Lzw::_output (

array $data

): void

Adds the given data to the output.

Parameters

$data : array

uncompress()

public Lzw::uncompress (

void

): array

Uncompresses the LZW data of a GIF image.

Exceptions

Throws \setasign\SetaPDF2\Core\Image\Exception