tecnickcom / tc-lib-pdf-filter

2.11.2 2026-09-05 07:32 UTC

Requires

• php: ^8.2
• ext-pcre: *
• ext-zlib: *

Requires (Dev)

• carthage-software/mago: 1.47.6
• pdepend/pdepend: ^2.16
• phpunit/phpunit: ^11.5 || ^12.5 || ^13.3

Suggests

• ext-imagick: Required for the JPXDecode (JPEG 2000) and CCITTFaxDecode filters
• jbig2dec: CLI tool required for the JBIG2Decode filter

LGPL-3.0-or-later

• Nicola Asuni

• compression
• pdf
• filter
• encryption
• tc-lib-pdf-filter

Published on Packagist.org on 2026-09-05 07:32 UTC

README

Decoder library for standard PDF stream filters.

💖 Part of the tc-lib-pdf / TCPDF ecosystem (100M+ installs). Sponsor its maintenance →

Overview

tc-lib-pdf-filter decodes the stream filters defined by the PDF specification (PDF 32000-1:2008 §7.4), one at a time or as a chain, with the DecodeParms of each filter.

Namespace	\Com\Tecnick\Pdf\Filter
Author	Nicola Asuni [e-mail]
License	GNU LGPL v3 - see LICENSE
API docs	https://tcpdf.org/docs/srcdoc/tc-lib-pdf-filter
Packagist	https://packagist.org/packages/tecnickcom/tc-lib-pdf-filter

Features

PDF Filters

• FlateDecode, LZWDecode, RunLengthDecode
• ASCIIHexDecode, ASCII85Decode
• CCITTFaxDecode, DCTDecode, JPXDecode, JBIG2Decode
• Crypt (Identity and None)

API

• Decode one filter, or a chain of filters applied in order
• DecodeParms as a single dictionary or as an array parallel to Filter
• Predictor (TIFF and PNG) for FlateDecode and LZWDecode
• Filter names as the full name, the inline-image abbreviation, or a FilterType enum case
• A single exception class for unknown filters and malformed streams

Requirements

• PHP 8.2 or later
• Extensions: zlib, pcre
• Composer

Optional:

• Extension imagick: required by CCITTFaxDecode and JPXDecode
• CLI tool jbig2dec: required by JBIG2Decode

Without them those three filters throw; the others are unaffected.

Decode parameters

DecodeParms entries are passed to decode() and decodeAll() as an array. Beyond the parameters defined by the PDF specification, three filters accept one more:

Parameter	Filters	Meaning
MaxOutputSize	FlateDecode, LZWDecode, RunLengthDecode	Decoded-size cap in bytes; 0 (default) = unlimited

FlateDecode reaches compression ratios above 1000:1, so callers decoding untrusted documents should set MaxOutputSize to bound decompression bombs.

CCITTFaxDecode derives the image height from Rows. When Rows is absent the height is estimated from the encoded length, which under-estimates it and truncates the image, so pass Rows (the image dictionary /Height).

Installation

composer require tecnickcom/tc-lib-pdf-filter

Quick Start

<?php

require_once __DIR__ . '/vendor/autoload.php';

$filter = new \Com\Tecnick\Pdf\Filter\Filter();
$decoded = $filter->decodeAll(['ASCIIHexDecode', 'FlateDecode'], $data);

Development

make deps
make help
make qa

Packaging

make rpm
make deb

For system packages, bootstrap with:

require_once '/usr/share/php/Com/Tecnick/Pdf/Filter/autoload.php';

Contributing

Contributions are welcome. Please review CONTRIBUTING.md, CODE_OF_CONDUCT.md, and SECURITY.md.