libtiff(3tiff)
NAME
libtiff - introduction to libtiff, a library for reading and writing TIFF files
SYNOPSIS
#include <tiffio.h> cc file.c -ltiff
DESCRIPTION
libtiff is a library for reading and writing data files encoded with the 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. The library supports several compression algorithms, as indicated by the Compression field, including: no compression (1), CCITT 1D Huffman compression (2), CCITT Group 3 Facsimile compression (3), 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 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 (MSB) to Least Significant Bit (LSB) or LSB to MSB. Finally, the library does not support files in which the BitsPerSample, Compression, MinSampleValue, or MaxSampleValue fields are defined differently on a per-sample basis (in Rev. 6.0 the Compression tag is not defined on a per-sample basis, so this is immaterial).
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
TIFF format. The following typedefs are exposed to users either
through function definitions or through parameters passed through the
varargs interfaces.
typedef unsigned short uint16; 16-bit unsigned integer
typedef unsigned <thing> uint32; 32-bit unsigned integer
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
Note that tstrip_t, ttile_t, and tsize_t are constrained to be no more
than 32-bit quantities by 32-bit fields they are stored in in the TIFF
image. Likewise tsample_t is limited by the 16-bit field used to store
the SamplesPerPixel tag. tdir_t constrains the maximum number of IFDs
that may appear in an image and may be an arbitrary size (w/o penalty).
ttag_t must be either int, unsigned int, pointer, or double because the
library uses a varargs interface and ANSI C restricts the type of the
parameter before an ellipsis to be a promoted type. 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.
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.
Name Description
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
TIFFFieldDataType get data type from field information
TIFFFieldName get field name from field information
TIFFFieldPassCount get whether to pass a value count to Get/SetField
TIFFFieldReadCount get number of values to be read from field
TIFFFieldTag get tag value from field information
TIFFFieldWithName get field information given field name
TIFFFieldWithTag get field information given tag
TIFFFieldWriteCount get number of values to be written to field
TIFFFileName return name of open file
TIFFFileno return open file descriptor
TIFFFindCODEC find standard codec for the specific scheme
TIFFFindField get field information given tag and data type
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
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
TAG USAGE
The table below lists the 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. Group3Options is only useful if Compression is set to CCITT Group 3 encoding. Tags of this sort are considered codec- specific tags and the library does not recognize them except when the Compression tag has been previously set to the relevant compression scheme. Tag Name Value R/W Library Use/Notes 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/Wused 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
PSEUDO TAGS
In addition to the normal TIFF tags the library supports a collection
of tags whose values lie in a range outside the valid range of TIFF
tags. These tags are termed pseud-tags and are used to control various
codec-specific functions within the library. The table below
summarizes the defined pseudo-tags.
Tag Name Codec R/W Library Use/Notes
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 JPEGTables tag
TIFFTAG_ZIPQUALITY Deflate R/Wcompression quality level
TIFFTAG_PIXARLOGDATAFMT PixarLog R/Wuser data format
TIFFTAG_PIXARLOGQUALITY PixarLog R/Wcompression quality level
TIFFTAG_SGILOGDATAFMT SGILog R/W user data format
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 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 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.
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.
TIFFTAG_IPTCNEWSPHOTO
Tag contaings image metadata per the IPTC newsphoto spec:
Headline, captioning, credit, etc... Used by most wire services.
TIFFTAG_PHOTOSHOP
Tag contains Photoshop captioning information and metadata.
Photoshop uses in parallel and redundantly alongside
IPTCNEWSPHOTO information.
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.
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.
TIFFTAG_JPEGTABLESMODE
Control the information written in the 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.
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.
TIFFTAG_PIXARLOGDATAFMT
Control the format of user data passed in to the PixarLog codec
when encoding and passed 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.
TIFFTAG_PIXARLOGQUALITY
Control the compression technique used by the PixarLog codec.
This value is treated identically to TIFFTAG_ZIPQUALITY; see the
above description.
TIFFTAG_SGILOGDATAFMT
Control the format of client data passed in to the SGILog codec
when encoding and passed 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).
DIAGNOSTICS
All error messages are directed through the TIFFError routine. By default messages are directed to stderr in the form: module: message\n. Warning messages are likewise directed through the TIFFWarning routine.
SEE ALSO
fax2tiff(1), gif2tiff(1), pal2rgb(1), ppm2tiff(1), rgb2ycbcr(1), ras2tiff(1), raw2tiff(1), sgi2tiff(1), tiff2bw(1), tiffdither(1), tiffdump(1), tiffcp(1), tiffcmp(1), tiffgt(1), tiffinfo(1), tiffmedian(1), tiffsplit(1), tiffsv(1). Tag Image File Format Specification --- Revision 6.0, an Aldus Technical Memorandum. The Spirit of TIFF Class F, an appendix to the TIFF 5.0 specification prepared by Cygnet Technologies. Libtiff library home page: http://www.simplesystems.org/libtiff/
BUGS
The library does not support multi-sample images where some samples have different bits/sample. The library does not support random access to compressed data that is organized with more than one row per tile or strip.
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
