.\" $Id: libtiff.3tiff,v 1.3 2005/11/02 11:07:19 dron Exp $
.\"
.\" Copyright (c) 1988-1997 Sam Leffler
.\" Copyright (c) 1991-1997 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
.\" all copies of the software and related documentation, and (ii) the names of
.\" Sam Leffler and Silicon Graphics may not be used in any advertising or
.\" publicity relating to the software without the specific, prior written
.\" permission of Sam Leffler and Silicon Graphics.
.\"
.\" THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
.\" EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
.\" 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
.\" LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
.\" OF THIS SOFTWARE.
.\"
.if n .po 0
.TH INTRO 3TIFF "November 2, 2005" "libtiff"
.SH NAME
libtiff \- introduction to
.IR libtiff ,
a library for reading and writing
.SM TIFF
files
.SH SYNOPSIS
.B "#include <tiffio.h>"
.sp
cc file.c
.B -ltiff
.SH DESCRIPTION
.I libtiff
is a library for reading and writing data files encoded with the
.I "Tag Image File"
format, Revision 6.0 (or revision 5.0 or revision 4.0). This file format is
suitable for archiving multi-color and monochromatic image data.
.PP
The library supports several compression algorithms, as indicated by the
.I Compression
field, including:
no compression (1),
.SM CCITT
1D Huffman compression (2),
.SM CCITT
Group 3 Facsimile compression (3),
.SM CCITT
Group 4 Facsimile compression (4),
Lempel-Ziv & Welch compression (5),
baseline JPEG compression (7),
word-aligned 1D Huffman compression (32771),
and
PackBits compression (32773).
In addition, several nonstandard compression algorithms are supported: the
4-bit compression algorithm used by the
.I ThunderScan
program (32809) (decompression only), NeXT's 2-bit compression algorithm
(32766) (decompression only), an experimental LZ-style algorithm known as
Deflate (32946), and an experimental CIE LogLuv compression scheme designed
for images with high dynamic range (32845 for LogL and 32845 for LogLuv).
Directory information may be in either little- or big-endian byte order\-byte
swapping is automatically done by the library. Data bit ordering may be either
Most Significant Bit (\c
.SM MSB\c
) to Least Significant Bit (\c
.SM LSB\c
) or
.SM LSB
to
.SM MSB.
Finally, the library does not support files in which the
.IR BitsPerSample ,
.IR Compression ,
.IR MinSampleValue ,
or
.IR MaxSampleValue
fields are defined differently on a per-sample basis
(in Rev. 6.0 the
.I Compression
tag is not defined on a per-sample basis, so this is immaterial).
.SH "DATA TYPES"
The library makes extensive use of C typedefs to promote portability.
Two sets of typedefs are used, one for communication with clients
of the library and one for internal data structures and parsing of the
.SM TIFF
format.
The following typedefs are exposed to users either through function
definitions or through parameters passed through the varargs interfaces.
.in +.5i
.sp 5p
.ta +\w'typedef unsigned <\fIthing\fP> uint32; 'u
.nf
typedef unsigned short uint16; 16-bit unsigned integer
typedef unsigned <\fIthing\fP> uint32; 32-bit unsigned integer
.sp 5p
typedef unsigned int ttag_t; directory tag
typedef uint16 tdir_t; directory index
typedef uint16 tsample_t; sample number
typedef uint32 tstrip_t; strip number
typedef uint32 ttile_t; tile number
typedef int32 tsize_t; i/o size in bytes
typedef void* tdata_t; image data ref
typedef void* thandle_t; client data handle
typedef int32 toff_t; file offset
.fi
.sp 5p
.in -.5i
Note that
.IR tstrip_t ,
.IR ttile_t ,
and
.I tsize_t
are constrained to be no more than 32-bit quantities by 32-bit fields they are
stored in in the
.SM TIFF
image.
Likewise
.I tsample_t
is limited by the 16-bit field used to store the
.I SamplesPerPixel
tag.
.I tdir_t
constrains the maximum number of
.SM IFDs
that may appear in an image and may be an arbitrary size (w/o penalty).
.I ttag_t
must be either int, unsigned int, pointer, or double because the library uses
a varargs interface and
.SM "ANSI C"
restricts the type of the parameter before an ellipsis to be a promoted type.
.I toff_t
is defined as int32 because TIFF file offsets are (unsigned) 32-bit
quantities. A signed value is used because some interfaces return \-1 on
error. Finally, note that user-specified data references are passed as opaque
handles and only cast at the lowest layers where their type is presumed.
.SH "LIST OF ROUTINES"
The following routines are part of the library. Consult specific manual pages
for details on their operation; on most systems doing ``man function-name''
will work.
.sp
.nf
.ta \w'TIFFCheckpointDirectory'u+2n
\fIName\fP \fIDescription\fP
.sp 5p
TIFFCheckpointDirectory writes the current state of the directory
TIFFCheckTile very x,y,z,sample is within image
TIFFCIELabToRGBInit initialize CIE L*a*b* 1976 to RGB conversion state
TIFFCIELabToXYZ perform CIE L*a*b* 1976 to CIE XYZ conversion
TIFFClientOpen open a file for reading or writing
TIFFClose close an open file
TIFFComputeStrip return strip containing y,sample
TIFFComputeTile return tile containing x,y,z,sample
TIFFCurrentDirectory return index of current directory
TIFFCurrentRow return index of current scanline
TIFFCurrentStrip return index of current strip
TIFFCurrentTile return index of current tile
TIFFDataWidth return the size of TIFF data types
TIFFError library error handler
TIFFFdOpen open a file for reading or writing
TIFFFileName return name of open file
TIFFFileno return open file descriptor
TIFFFindCODEC find standard codec for the specific scheme
TIFFFlush flush all pending writes
TIFFFlushData flush pending data writes
TIFFGetBitRevTable return bit reversal table
TIFFGetField return tag value in current directory
TIFFGetFieldDefaulted return tag value in current directory
TIFFGetMode return open file mode
TIFFGetVersion return library version string
TIFFIsCODECConfigured check, whether we have working codec
TIFFIsMSB2LSB return true if image data is being returned
with bit 0 as the most significant bit
TIFFIsTiled return true if image data is tiled
TIFFIsByteSwapped return true if image data is byte-swapped
TIFFNumberOfStrips return number of strips in an image
TIFFNumberOfTiles return number of tiles in an image
TIFFOpen open a file for reading or writing
TIFFPrintDirectory print description of the current directory
TIFFReadBufferSetup specify i/o buffer for reading
TIFFReadDirectory read the next directory
TIFFReadEncodedStrip read and decode a strip of data
TIFFReadEncodedTile read and decode a tile of data
TIFFReadRawStrip read a raw strip of data
TIFFReadRawTile read a raw tile of data
TIFFReadRGBAImage read an image into a fixed format raster
TIFFReadScanline read and decode a row of data
TIFFReadTile read and decode a tile of data
TIFFRegisterCODEC override standard codec for the specific scheme
TIFFReverseBits reverse bits in an array of bytes
TIFFRGBAImageBegin setup decoder state for TIFFRGBAImageGet
TIFFRGBAImageEnd release TIFFRGBAImage decoder state
TIFFRGBAImageGet read and decode an image
TIFFRGBAImageOK is image readable by TIFFRGBAImageGet
TIFFScanlineSize return size of a scanline
TIFFSetDirectory set the current directory
TIFFSetSubDirectory set the current directory
TIFFSetErrorHandler set error handler function
TIFFSetField set a tag's value in the current directory
TIFFSetWarningHandler set warning handler function
TIFFStripSize returns size of a strip
TIFFRawStripSize returns the number of bytes in a raw strip
TIFFSwabShort swap bytes of short
TIFFSwabLong swap bytes of long
TIFFSwabArrayOfShort swap bytes of an array of shorts
TIFFSwabArrayOfLong swap bytes of an array of longs
TIFFTileRowSize return size of a row in a tile
TIFFTileSize return size of a tile
TIFFUnRegisterCODEC unregisters the codec
TIFFVGetField return tag value in current directory
TIFFVGetFieldDefaulted return tag value in current directory
TIFFVSetField set a tag's value in the current directory
TIFFVStripSize returns the number of bytes in a strip
TIFFWarning library warning handler
TIFFWriteDirectory write the current directory
TIFFWriteEncodedStrip compress and write a strip of data
TIFFWriteEncodedTile compress and write a tile of data
TIFFWriteRawStrip write a raw strip of data
TIFFWriteRawTile write a raw tile of data
TIFFWriteScanline write a scanline of data
TIFFWriteTile compress and write a tile of data
TIFFXYZToRGB perform CIE XYZ to RGB conversion
TIFFYCbCrToRGBInit initialize YCbCr to RGB conversion state
TIFFYCbCrtoRGB perform YCbCr to RGB conversion
.sp
Auxiliary functions:
_TIFFfree free memory buffer
_TIFFmalloc dynamically allocate memory buffer
_TIFFmemcmp compare contents of the memory buffers
_TIFFmemcpy copy contents of the one buffer to another
_TIFFmemset fill memory buffer with a constant byte
_TIFFrealloc dynamically reallocate memory buffer
.fi
.SH "TAG USAGE"
The table below lists the
.SM TIFF
tags that are recognized and handled by the library.
If no use is indicated in the table, then the library
reads and writes the tag, but does not use it internally.
Note that some tags are meaningful only when a particular
compression scheme is being used; e.g.
.I Group3Options
is only useful if
.I Compression
is set to
.SM CCITT
Group 3 encoding.
Tags of this sort are considered
.I codec-specific
tags and the library does not recognize them except when the
.I Compression
tag has been previously set to the relevant compression scheme.
.sp
.nf
.ta \w'TIFFTAG_JPEGTABLESMODE'u+2n +\w'Value'u+2n +\w'R/W'u+2n
\fITag Name\fP \fIValue\fP \fIR/W\fP \fILibrary Use/Notes\fP
.sp 5p
.nf
Artist 315 R/W
BadFaxLines 326 R/W
BitsPerSample 258 R/W lots
CellLength 265 parsed but ignored
CellWidth 264 parsed but ignored
CleanFaxData 327 R/W
ColorMap 320 R/W
ColorResponseUnit 300 parsed but ignored
Compression 259 R/W choosing codec
ConsecutiveBadFaxLines 328 R/W
Copyright 33432 R/W
DataType 32996 R obsoleted by SampleFormat tag
DateTime 306 R/W
DocumentName 269 R/W
DotRange 336 R/W
ExtraSamples 338 R/W lots
FaxRecvParams 34908 R/W
FaxSubAddress 34909 R/W
FaxRecvTime 34910 R/W
FillOrder 266 R/W control bit order
FreeByteCounts 289 parsed but ignored
FreeOffsets 288 parsed but ignored
GrayResponseCurve 291 parsed but ignored
GrayResponseUnit 290 parsed but ignored
Group3Options 292 R/W used by Group 3 codec
Group4Options 293 R/W
HostComputer 316 R/W
ImageDepth 32997 R/W tile/strip calculations
ImageDescription 270 R/W
ImageLength 257 R/W lots
ImageWidth 256 R/W lots
InkNames 333 R/W
InkSet 332 R/W
JPEGTables 347 R/W used by JPEG codec
Make 271 R/W
Matteing 32995 R obsoleted by ExtraSamples tag
MaxSampleValue 281 R/W
MinSampleValue 280 R/W
Model 272 R/W
NewSubFileType 254 R/W called SubFileType in spec
NumberOfInks 334 R/W
Orientation 274 R/W
PageName 285 R/W
PageNumber 297 R/W
PhotometricInterpretation 262 R/W used by Group 3 and JPEG codecs
PlanarConfiguration 284 R/W data i/o
Predictor 317 R/W used by LZW and Deflate codecs
PrimaryChromacities 319 R/W
ReferenceBlackWhite 532 R/W
ResolutionUnit 296 R/W used by Group 3 codec
RowsPerStrip 278 R/W data i/o
SampleFormat 339 R/W
SamplesPerPixel 277 R/W lots
SMinSampleValue 340 R/W
SMaxSampleValue 341 R/W
Software 305 R/W
StoNits 37439 R/W
StripByteCounts 279 R/W data i/o
StripOffsets 273 R/W data i/o
SubFileType 255 R/W called OSubFileType in spec
TargetPrinter 337 R/W
Thresholding 263 R/W
TileByteCounts 324 R/W data i/o
TileDepth 32998 R/W tile/strip calculations
TileLength 323 R/W data i/o
TileOffsets 324 R/W data i/o
TileWidth 322 R/W data i/o
TransferFunction 301 R/W
WhitePoint 318 R/W
XPosition 286 R/W
XResolution 282 R/W
YCbCrCoefficients 529 R/W used by TIFFRGBAImage support
YCbCrPositioning 531 R/W tile/strip size calulcations
YCbCrSubsampling 530 R/W
YPosition 286 R/W
YResolution 283 R/W used by Group 3 codec
.SH "PSEUDO TAGS"
In addition to the normal
.SM TIFF
tags the library supports a collection of
tags whose values lie in a range outside the valid range of
.SM TIFF
tags.
These tags are termed
.I pseud-tags
and are used to control various codec-specific functions within the library.
The table below summarizes the defined pseudo-tags.
.sp
.nf
.ta \w'TIFFTAG_JPEGTABLESMODE'u+2n +\w'Codec'u+2n +\w'R/W'u+2n
\fITag Name\fP \fICodec\fP \fIR/W\fP \fILibrary Use/Notes\fP
.sp 5p
.nf
TIFFTAG_FAXMODE G3 R/W general codec operation
TIFFTAG_FAXFILLFUNC G3/G4 R/W bitmap fill function
TIFFTAG_JPEGQUALITY JPEG R/W compression quality control
TIFFTAG_JPEGCOLORMODE JPEG R/W control colorspace conversions
TIFFTAG_JPEGTABLESMODE JPEG R/W control contents of \fIJPEGTables\fP tag
TIFFTAG_ZIPQUALITY Deflate R/W compression quality level
TIFFTAG_PIXARLOGDATAFMT PixarLog R/W user data format
TIFFTAG_PIXARLOGQUALITY PixarLog R/W compression quality level
TIFFTAG_SGILOGDATAFMT SGILog R/W user data format
.fi
.TP
.B TIFFTAG_FAXMODE
Control the operation of the Group 3 codec.
Possible values (independent bits that can be combined by
or'ing them together) are:
FAXMODE_CLASSIC
(enable old-style format in which the
.SM RTC
is written at the end of the last strip),
FAXMODE_NORTC
(opposite of
FAXMODE_CLASSIC;
also called
FAXMODE_CLASSF),
FAXMODE_NOEOL
(do not write
.SM EOL
codes at the start of each row of data),
FAXMODE_BYTEALIGN
(align each encoded row to an 8-bit boundary),
FAXMODE_WORDALIGN
(align each encoded row to an 16-bit boundary),
The default value is dependent on the compression scheme; this
pseudo-tag is used by the various G3 and G4 codecs to share code.
.TP
.B TIFFTAG_FAXFILLFUNC
Control the function used to convert arrays of black and white
runs to packed bit arrays.
This hook can be used to image decoded scanlines in multi-bit
depth rasters (e.g. for display in colormap mode)
or for other purposes.
The default value is a pointer to a builtin function that images
packed bilevel data.
.TP
.B TIFFTAG_IPTCNEWSPHOTO
Tag contaings image metadata per the IPTC newsphoto spec: Headline,
captioning, credit, etc... Used by most wire services.
.TP
.B TIFFTAG_PHOTOSHOP
Tag contains Photoshop captioning information and metadata. Photoshop
uses in parallel and redundantly alongside IPTCNEWSPHOTO information.
.TP
.B TIFFTAG_JPEGQUALITY
Control the compression quality level used in the baseline algorithm.
Note that quality levels are in the range 0-100 with a default value of 75.
.TP
.B TIFFTAG_JPEGCOLORMODE
Control whether or not conversion is done between
RGB and YCbCr colorspaces.
Possible values are:
JPEGCOLORMODE_RAW
(do not convert), and
JPEGCOLORMODE_RGB
(convert to/from RGB)
The default value is JPEGCOLORMODE_RAW.
.TP
.B TIFFTAG_JPEGTABLESMODE
Control the information written in the
.I JPEGTables
tag.
Possible values (independent bits that can be combined by
or'ing them together) are:
JPEGTABLESMODE_QUANT
(include quantization tables),
and
JPEGTABLESMODE_HUFF
(include Huffman encoding tables).
The default value is JPEGTABLESMODE_QUANT|JPEGTABLESMODE_HUFF.
.TP
.B TIFFTAG_ZIPQUALITY
Control the compression technique used by the Deflate codec.
Quality levels are in the range 1-9 with larger numbers yielding better
compression at the cost of more computation.
The default quality level is 6 which yields a good time-space tradeoff.
.TP
.B TIFFTAG_PIXARLOGDATAFMT
Control the format of user data passed
.I in
to the PixarLog codec when encoding and passed
.I out
from when decoding.
Possible values are:
PIXARLOGDATAFMT_8BIT
for 8-bit unsigned pixels,
PIXARLOGDATAFMT_8BITABGR
for 8-bit unsigned ABGR-ordered pixels,
PIXARLOGDATAFMT_11BITLOG
for 11-bit log-encoded raw data,
PIXARLOGDATAFMT_12BITPICIO
for 12-bit PICIO-compatible data,
PIXARLOGDATAFMT_16BIT
for 16-bit signed samples,
and
PIXARLOGDATAFMT_FLOAT
for 32-bit IEEE floating point samples.
.TP
.B TIFFTAG_PIXARLOGQUALITY
Control the compression technique used by the PixarLog codec.
This value is treated identically to TIFFTAG_ZIPQUALITY; see the
above description.
.TP
.B TIFFTAG_SGILOGDATAFMT
Control the format of client data passed
.I in
to the SGILog codec when encoding and passed
.I out
from when decoding.
Possible values are:
SGILOGDATAFMT_FLTXYZ
for converting between LogLuv and 32-bit IEEE floating valued XYZ pixels,
SGILOGDATAFMT_16BITLUV
for 16-bit encoded Luv pixels,
SGILOGDATAFMT_32BITRAW and SGILOGDATAFMT_24BITRAW
for no conversion of data,
SGILOGDATAFMT_8BITRGB
for returning 8-bit RGB data (valid only when decoding LogLuv-encoded data),
SGILOGDATAFMT_FLTY
for converting between LogL and 32-bit IEEE floating valued Y pixels,
SGILOGDATAFMT_16BITL
for 16-bit encoded L pixels,
and
SGILOGDATAFMT_8BITGRY
for returning 8-bit greyscale data
(valid only when decoding LogL-encoded data).
.SH DIAGNOSTICS
All error messages are directed through the
.IR TIFFError
routine.
By default messages are directed to
.B stderr
in the form:
.IR "module: message\en."
Warning messages are likewise directed through the
.IR TIFFWarning
routine.
.SH "SEE ALSO"
.BR fax2tiff (1),
.BR gif2tiff (1),
.BR pal2rgb (1),
.BR ppm2tiff (1),
.BR rgb2ycbcr (1),
.BR ras2tiff (1),
.BR raw2tiff (1),
.BR sgi2tiff (1),
.BR tiff2bw (1),
.BR tiffdither (1),
.BR tiffdump (1),
.BR tiffcp (1),
.BR tiffcmp (1),
.BR tiffgt (1),
.BR tiffinfo (1),
.BR tiffmedian (1),
.BR tiffsplit (1),
.BR tiffsv (1).
.PP
.BR "Tag Image File Format Specification \(em Revision 6.0" ,
an Aldus Technical Memorandum.
.PP
.BR "The Spirit of TIFF Class F" ,
an appendix to the TIFF 5.0 specification prepared by Cygnet Technologies.
.PP
Libtiff library home page:
.BR http://www.remotesensing.org/libtiff/
.SH BUGS
The library does not support multi-sample images
where some samples have different bits/sample.
.PP
The library does not support random access to compressed data
that is organized with more than one row per tile or strip.
|
