CTS logo
hazy blue Catskill Mountains in distance


A Thought…

My mother raised 8 children and always made two choices for dinner — “take it” or “leave it”.

   — Charles Ransdell, Calvin and Hobbes comic letters


PDF::Builder::Basic::PDF::Filter - Abstract superclass for PDF stream filters


    $f = PDF::Builder::Basic::PDF::Filter->new();
    $str = $f->outfilt($str, 1);
    print OUTFILE $str;

    while (read(INFILE, $dat, 4096))
    { $store .= $f->infilt($dat, 0); }
    $store .= $f->infilt("", 1);


A Filter object contains state information for the process of outputting and inputting data through the filter. The precise state information stored is up to the particular filter and may range from nothing to whole objects created and destroyed.

Each filter stores different state information for input and output and thus may handle one input filtering process and one output filtering process at the same time.



Creates a new filter object with empty state information ready for processing data both input and output.


    $dat = $f->infilt($str, $isend)
Filters from output to input the data. Notice that $isend == 0 implies that there is more data to come and so following it $f may contain state information (usually due to the break-off point of $str not being tidy). Subsequent calls will incorporate this stored state information.
$isend == 1 implies that there is no more data to follow. The final state of $f will be that the state information is empty. Error messages are most likely to occur here since if there is required state information to be stored following this data, then that would imply an error in the data.


    $str = $f->outfilt($dat, $isend)
Filter stored data ready for output. Parallels infilt.


Up (Parents)

Master Index
PDF::Builder -- Facilitates the creation and modification of PDF files
PDF::Builder::Basic::PDF -- Various utilities and support routines


PDF::Builder::Basic::PDF::Array -- Corresponds to a PDF array
PDF::Builder::Basic::PDF::Bool -- Holds the strings true or false
PDF::Builder::Basic::PDF::Dict -- PDF Dictionaries and Streams
PDF::Builder::Basic::PDF::File -- Holds the trailers and cross-reference tables for a PDF file
PDF::Builder::Basic::PDF::Literal -- Literal PDF Object
PDF::Builder::Basic::PDF::Name -- Stores PDF names (things beginning with /)
PDF::Builder::Basic::PDF::Null -- PDF Null type object
PDF::Builder::Basic::PDF::Number -- Numbers in PDF
PDF::Builder::Basic::PDF::Objind -- PDF indirect object reference
PDF::Builder::Basic::PDF::Page -- Represents a PDF page
PDF::Builder::Basic::PDF::Pages -- PDF pages hierarchical element
PDF::Builder::Basic::PDF::String -- PDF String type objects
PDF::Builder::Basic::PDF::Utils -- Utility functions for PDF library

Down (Children)

PDF::Builder::Basic::PDF::Filter::ASCII85Decode -- Compress and uncompress stream filters for ASCII-85
PDF::Builder::Basic::PDF::Filter::ASCIIHexDecode -- Compress and uncompress stream filters for ASCII-Hex
PDF::Builder::Basic::PDF::Filter::CCITTFaxDecode -- Compress and uncompress stream filters for CCITTFax - NOT FULLY IMPLEMENTED
PDF::Builder::Basic::PDF::Filter::FlateDecode -- Compress and uncompress stream filters for Flate
PDF::Builder::Basic::PDF::Filter::LZWDecode -- Compress and uncompress stream filters for Lempel-Ziv-Welch
PDF::Builder::Basic::PDF::Filter::RunLengthDecode -- Compress and uncompress stream filters for Run-Length


All content © copyright 2005 – 2024 by Catskill Technology Services, LLC.
All rights reserved.
Note that Third Party software (whether Open Source or proprietary) on this site remains under the copyright and license of its owners. Catskill Technology Services, LLC does not claim copyright over such software.


This page is https://www.catskilltech.com/Documentation/PDF/Builder/Basic/PDF/Filter.html

Search Quotations database.

Last updated Sat, 09 Dec 2023 at 10:59 PM

Valid HTML 5

Thu, 18 Apr 2024 at 9:53 AM EDT