tiffcodec.3t

tiff文件开发库

.\" $Header: /cvsroot/osrs/libtiff/man/TIFFcodec.3t,v 1.2 2003/11/20 21:53:40 dron Exp $
.\"
.\" Copyright (c) 1995 Sam Leffler
.\" Copyright (c) 1995 Silicon Graphics, Inc.
.\"
.\" Permission to use, copy, modify, distribute, and sell this software and 
.\" its documentation for any purpose is hereby granted without fee, provided
.\" that (i) the above copyright notices and this permission notice appear in
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.\" Sam Leffler and Silicon Graphics may not be used in any advertising or
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.\" THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
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.\" WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
.\" 
.\" IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
.\" ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
.\" OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
.\" WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
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.\" OF THIS SOFTWARE.
.\"
.if n .po 0
.TH CODEC 3T "October 15, 1995"
.SH NAME
TIFFFindCODEC, TIFFRegisterCODEC, TIFFUnRegisterCODEC \- codec-related utility routines
.SH SYNOPSIS
.B "#include <tiffio.h>"
.br
.B "const TIFFCodec* TIFFFindCODEC(uint16 scheme);"
.br
.B "TIFFCodec* TIFFRegisterCODEC(uint16 scheme, const char* method, TIFFInitMethod init);"
.br
.B "void TIFFUnRegisterCODEC(TIFFCodec* codec);"
.br
.B "int TIFFIsCODECConfigured(uint16 scheme);"
.SH DESCRIPTION
.I libtiff
supports a variety of compression schemes implemented by software
.IR codecs .
Each codec adheres to a modular interface that provides for
the decoding and encoding of image data; as well as some other
methods for initialization, setup, cleanup, and the control
of default strip and tile sizes.
Codecs are identified by the associated value of the 
.SM TIFF
.I Compression
tag; e.g. 5 for
.SM LZW
compression.
.PP
The
.I TIFFRegisterCODEC
routine can be used to
augment or override the set of codecs available to an application.
If the specified
.I scheme
already has a registered codec then it is
.I overridden
and any images with data encoded with this
compression scheme will be decoded using the supplied coded.
.PP
.I TIFFIsCODECConfigured
returns 1 if the codec is configured and working. Otherwise 0 will be returned.
.SH DIAGNOSTICS
.BR "No space to register compression scheme %s" .
.I TIFFRegisterCODEC
was unable to allocate memory for the data structures needed
to register a codec.
.PP
.BR "Cannot remove compression scheme %s; not registered" .
.I TIFFUnRegisterCODEC
did not locate the specified codec in the table of registered 
compression schemes.
.SH "SEE ALSO"
.IR libtiff (3T)