libtiff

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), 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 uint32_t ttag_t;    // directory tag
typedef uint16_t tdir_t;    // directory index
typedef uint16_t tsample_t; // sample number
typedef uint32_t tstrip_t;  // strip number
typedef uint32_t ttile_t;   // tile number
typedef int64_t tmsize_t;   // signed size type (int32_t on 32-bit platforms)
typedef tmsize_t tsize_t;   // i/o size in bytes
typedef void* tdata_t;      // image data ref
typedef void* thandle_t;    // client data handle
typedef uint64_t 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 C restricts the type of the parameter before an ellipsis to be a promoted type. toff_t is defined as uint64_t because TIFF file offsets are (unsigned) 32-bit quantities, and BigTIFF file offsets are unsigned 64-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.

Libtiff functions

Name

Description

TIFFAccessTagMethods()

provides read/write access to the TIFFTagMethods within the TIFF structure to application code without giving access to the private TIFF structure

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

TIFFCleanup()

auxiliary function to free the TIFF structure

TIFFClientdata()

return open file's clientdata handle

TIFFClientOpen()

open a file for reading or writing

TIFFClose()

close a previously opened TIFF file

TIFFComputeStrip()

return strip containing y,sample

TIFFComputeTile()

return tile containing x,y,z,sample

TIFFCreateCustomDirectory()

setup for a custom directory in a open TIFF file

TIFFCreateDirectory()

setup for a directory in a open TIFF file

TIFFCreateEXIFDirectory()

setup for a EXIF custom directory in a open TIFF file within a TIFF tag

TIFFCreateGPSDirectory()

setup for a GPS custom directory in a open TIFF file within a TIFF tag

TIFFCurrentDirectory()

return index of current directory

TIFFCurrentDirOffset()

return file offset of the current directory (instead of an index)

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

TIFFDefaultStripSize()

return number of rows for a reasonable-sized strip according to the current settings of the ImageWidth, BitsPerSample and SamplesPerPixel, tags and any compression-specific requirements

TIFFDefaultTileSize()

return pixel width and height of a reasonable-sized tile; suitable for setting up the TileWidth and TileLength tags

TIFFDeferStrileArrayWriting()

is an advanced writing function to control when/where the [Strip/Tile][Offsets/ByteCounts] arrays are written into the file, and must be used in a particular sequence together with TIFFForceStrileArrayWriting() (see description)

TIFFError()

library error handler printing to stderr

TIFFErrorExt()

library error handler printing to stderr and/or a file

TIFFFdOpen()

open a file for reading or writing

TIFFFieldDataType()

get data type from field information

TIFFFieldIsAnonymous()

returns if field was unknown to libtiff and has been auto-registered

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

TIFFFieldSetGetCountSize()

returns size of count parameter of TIFFSetField() and TIFFGetField()

TIFFFieldSetGetSize()

return data size in bytes of the field data type used for libtiff internal storage.

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

TIFFForceStrileArrayWriting()

is an advanced writing function that writes the [Strip/Tile][Offsets/ByteCounts] arrays at the end of the file (see description)

TIFFFreeDirectory()

release storage associated with a directory

TIFFGetBitRevTable()

return bit reversal table

TIFFGetClientInfo()

returns a pointer to the data of the named entry in the clientinfo-list

TIFFGetCloseProc()

returns a pointer to file close method

TIFFGetConfiguredCODECs()

gets list of configured codecs, both built-in and registered by user

TIFFGetField()

return tag value in current directory

TIFFGetFieldDefaulted()

return tag value in current directory with default value set if the value is not already set and a default is defined

TIFFGetMapFileProc()

returns a pointer to memory mapping method

TIFFGetMode()

return open file mode

TIFFGetReadProc()

returns a pointer to file read method

TIFFGetSeekProc()

returns a pointer to file seek method

TIFFGetSizeProc()

returns a pointer to file size requesting method

TIFFGetStrileByteCount()

return value of the TileByteCounts/StripByteCounts array for the specified tile/strile

TIFFGetStrileByteCountWithErr()

same as TIFFGetStrileByteCount() and additionally provides an error return

TIFFGetStrileOffset()

return value of the TileOffsets/StripOffsets array for the specified tile/strile

TIFFGetStrileOffsetWithErr()

same as TIFFGetStrileOffset() and additionally provides an error return

TIFFGetTagListCount()

return number of entries in the custom tag list

TIFFGetTagListEntry()

return tag number of the (n.th - 1) entry within the custom tag list

TIFFGetUnmapFileProc()

returns a pointer to memory unmapping method

TIFFGetVersion()

return library version string

TIFFGetWriteProc()

returns a pointer to file write method

TIFFIsBigEndian()

returns a non-zero value if the file is BigEndian and zero if the file is LittleEndian

TIFFIsBigTIFF()

returns a non-zero value if the file is in BigTIFF style

TIFFIsByteSwapped()

return true if image data is byte-swapped

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

TIFFIsUpSampled()

returns a non-zero value if image data returned through the read interface Routines is being up-sampled

TIFFLastDirectory()

returns a non-zero value if the current directory is the last directory in the file; otherwise zero is returned

TIFFMergeFieldInfo()

adds application defined TIFF tags to the list of known libtiff tags

TIFFNumberOfDirectories()

return number of directories in a file

TIFFNumberOfStrips()

return number of strips in an image

TIFFNumberOfTiles()

return number of tiles in an image

TIFFOpen()

open a file for reading or writing

TIFFOpenW()

opens a TIFF file with a Unicode filename, for read/writing

TIFFPrintDirectory()

print description of the current directory

TIFFRasterScanlineSize()

eturns the size in bytes of a complete decoded and packed raster scanline

TIFFRasterScanlineSize64()

return size as uint64_t

TIFFRawStripSize()

return number of bytes in a raw strip

TIFFRawStripSize64()

return number of bytes in a raw strip as uint64_t

TIFFReadBufferSetup()

specify i/o buffer for reading

TIFFReadCustomDirectory()

read the custom directory from the given offset and set the context of the TIFF-handle tif to that custom directory

TIFFReadDirectory()

read the next directory

TIFFReadEncodedStrip()

read and decode a strip of data

TIFFReadEncodedTile()

read and decode a tile of data

TIFFReadEXIFDirectory()

read the EXIF directory from the given offset and set the context of the TIFF-handle tif to that EXIF directory

TIFFReadFromUserBuffer()

replaces the use of TIFFReadEncodedStrip() / TIFFReadEncodedTile() when the user can provide the buffer for the input data

TIFFReadGPSDirectory()

read the GPS directory from the given offset and set the context of the TIFF-handle tif to that GPS directory

TIFFReadRawStrip()

read a raw strip of data

TIFFReadRawTile()

read a raw tile of data

TIFFReadRGBAImage()

read an image into a fixed format raster

TIFFReadRGBAImageOriented()

works like TIFFReadRGBAImage() except that the user can specify

the raster origin position

TIFFReadRGBAStrip()

reads a single strip of a strip-based image into memory, storing the result in the user supplied RGBA raster

TIFFReadRGBAStripExt()

same as TIFFReadRGBAStrip() but providing the paramater stop_on_error

TIFFReadRGBATile()

reads a single tile of a tile-based image into memory, storing the result in the user supplied RGBA raster

TIFFReadRGBATileExt()

same as TIFFReadRGBATile() but providing the paramater stop_on_error

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

TIFFRewriteDirectory()

operates similarly to TIFFWriteDirectory(), but can be called with directories previously read or written that already have an established location in the file and places it at the end of the file

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

TIFFScanlineSize64()

return size of a scanline as uint64_t

TIFFSetClientdata()

set open file's clientdata, and return previous value

TIFFSetClientInfo()

adds or replaces an entry in the clientinfo-list

TIFFSetCompressionScheme()

set compression scheme

TIFFSetDirectory()

set the current directory

TIFFSetErrorHandler()

set error handler function

TIFFSetErrorHandlerExt()

set error handler function with a file handle as parameter

TIFFSetField()

set a tag's value in the current directory

TIFFSetFileName()

sets the file name in the tif-structure and returns the old file name

TIFFSetFileno()

sets open file's I/O descriptor, and return previous value

TIFFSetMode()

sets the libtiff open mode in the tif-structure and returns the old mode

TIFFSetSubDirectory()

set the current directory

TIFFSetTagExtender()

is used to register the merge function for user defined tags as an extender callback with libtiff

TIFFSetupStrips()

TIFFSetWarningHandler()

set warning handler function

TIFFSetWarningHandlerExt()

set warning handler function with a file handle as parameter

TIFFSetWriteOffset()

set current write offset

TIFFStripSize()

return size of a strip

TIFFStripSize64()

return equivalent size for a strip of data as uint64_t

TIFFSwabArrayOfDouble()

swap bytes of an array of doubles

TIFFSwabArrayOfFloat()

swap bytes of an array of floats

TIFFSwabArrayOfLong()

swap bytes of an array of longs

TIFFSwabArrayOfLong8()

swap bytes of an array of uint64_t

TIFFSwabArrayOfShort()

swap bytes of an array of shorts

TIFFSwabArrayOfTriples()

swap the first and third byte of each triple within an array of bytes

TIFFSwabDouble()

swap bytes of double

TIFFSwabFloat()

swap bytes of float

TIFFSwabLong()

swap bytes of long

TIFFSwabLong8()

swap bytes of long long (uint64_t)

TIFFSwabShort()

swap bytes of short

TIFFTileRowSize()

return size of a row in a tile

TIFFTileRowSize64()

return size of a row in a tile as uint64_t

TIFFTileSize()

return size of a tile

TIFFTileSize64()

return size of a tile as uint64_t

TIFFUnlinkDirectory()

unlink the specified directory from the directory chain

TIFFUnRegisterCODEC()

unregisters the codec

TIFFUnsetField()

clear the contents of the field in the internal structure

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()

return number of bytes in a strip

TIFFVStripSize64()

return number of bytes in a strip with nrows rows of data as uint64_t

TIFFVTileSize()

returns the number of bytes in a row-aligned tile with nrows of data

TIFFVTileSize64()

returns the number of bytes in a row-alignedtile with nrows of data a uint64_t number

TIFFWarning()

library warning handler

TIFFWarningExt()

library warning handler printing to stderr and a file

TIFFWriteBufferSetup()

sets up the data buffer used to write raw (encoded) data to a file

TIFFWriteCheck()

verify file is writable and that the directory information is setup properly

TIFFWriteCustomDirectory()

write the current custom directory (also EXIF or GPS) to file

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

TIFFYCbCrtoRGB()

perform YCbCr to RGB conversion

TIFFYCbCrToRGBInit()

initialize YCbCr to RGB conversion state

Libtiff auxillary functions

Name

Description

_TIFFCheckMalloc()

checking for integer overflow before dynamically allocate memory buffer

_TIFFCheckRealloc()

checking for integer overflow before dynamically reallocate memory buffer

_TIFFClampDoubleToUInt32()

clamps double values into the range of uint32_t (i.e. 0 .. 0xFFFFFFFF)

_TIFFfree()

free memory buffer

_TIFFGetExifFields()

return a pointer to the libtiff internal definition list of the EXIF tags

_TIFFGetGpsFields()

return a pointer to the libtiff internal definition list of the GPS tags

_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

_TIFFMultiply32()

checks for an integer overflow of the multiplication result of uint32_t and return the multiplication result or 0 if an overflow would happen

_TIFFMultiply64()

checks for an integer overflow of the multiplication result of uint64_t and return the multiplication result or 0 if an overflow would happen

_TIFFrealloc()

dynamically reallocate memory buffer

_TIFFRewriteField()

Rewrite a field in the directory on disk without regard to updating the TIFF directory structure in memory

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.

libtiff supported tags

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/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 calculations

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 pseudo-tags and are used to control various codec-specific functions within the library. The table below summarizes the defined pseudo-tags.

libtiff supported 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/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

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 contains 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: 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, pal2rgb, ppm2tiff, rgb2ycbcr, raw2tiff, tiff2bw, tiffdither, tiffdump, tiffcp, tiff2cmp, tiffgt, tiffinfo, tiffmedian, tiffsplit,

"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.

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.