<title>TIFF 6.0 Specification Coverage</title>

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TIFF 6.0 Specification Coverage

          The library is capable of dealing with images that are written to

          follow the 5.0 or 6.0 TIFF spec.  There is also considerable support

          for some of the more esoteric portions of the 6.0 TIFF spec.

      Core requirements

          Both <tt>"MM"</tt> and <tt>"II"</tt> byte orders are handled.

          Both packed and separated planar configuration of samples.

          Any number of samples per pixel (memory permitting).

          Any image width and height (memory permitting).

          Multiple subfiles can be read and written.

          Editing is not supported in that related subfiles (e.g.

          a reduced resolution version of an image) are not automatically

          updated.

          Tags handled: <tt>ExtraSamples</tt>, <tt>ImageWidth</tt>,

          <tt>ImageLength</tt>, <tt>NewSubfileType</tt>, <tt>ResolutionUnit</tt>.

          <tt>Rowsperstrip</tt>, <tt>StripOffsets</tt>, <tt>StripByteCounts</tt>,

          <tt>XResolution</tt>, <tt>YResolution</tt>

      Tiled Images

      <tt>TileWidth</tt>, <tt>TileLength</tt>, <tt>TileOffsets</tt>,

        <tt>TileByteCounts</tt>

      Image Colorimetry Information

      <tt>WhitePoint</tt>, <tt>PrimaryChromaticities</tt>, <tt>TransferFunction</tt>,

        <tt>ReferenceBlackWhite</tt>

      Class B for bilevel images

      <tt>SamplesPerPixel</tt> = 1

        <tt>BitsPerSample</tt> = 1

        <tt>Compression</tt> = 1 (none), 2 (CCITT 1D), or 32773 (PackBits)

        <tt>PhotometricInterpretation</tt> = 0 (Min-is-White), 1 (Min-is-Black)

      Class G for grayscale images

      <tt>SamplesPerPixel</tt> = 1

        <tt>BitsPerSample</tt> = 4, 8

        <tt>Compression</tt> = 1 (none) 5 (LZW)

        <tt>PhotometricInterpretation</tt> = 0 (Min-is-White), 1 (Min-is-Black)

      Class P for palette color images

      <tt>SamplesPerPixel</tt> = 1

        <tt>BitsPerSample</tt> = 1-8

        <tt>Compression</tt> = 1 (none) 5 (LZW)

        <tt>PhotometricInterpretation</tt> = 3 (Palette RGB)

        <tt>ColorMap</tt>

      Class R for RGB full color images

      <tt>SamplesPerPixel</tt> = 3

        <tt>BitsPerSample</tt> = <8,8,8>

        <tt>PlanarConfiguration</tt> = 1, 2

        <tt>Compression</tt> = 1 (none) 5 (LZW)

        <tt>PhotometricInterpretation</tt> = 2 (RGB)

      Class F for facsimile

      (Class B tags plus...)

        <tt>Compression</tt> = 3 (CCITT Group 3), 4 (CCITT Group 4)

        <tt>FillOrder</tt> = 1 (MSB), 2 (LSB)

        <tt>Group3Options</tt> = 1 (2d encoding), 4 (zero fill), 5 (2d+fill)

        <tt>ImageWidth</tt> = 1728, 2048, 2482

        <tt>NewSubFileType</tt> = 2

        <tt>ResolutionUnit</tt> = 2 (Inch), 3 (Centimeter)

        <tt>PageNumber</tt>,

        <tt>XResolution</tt>,

        <tt>YResolution</tt>,

        <tt>Software</tt>,

        <tt>BadFaxLines</tt>,

        <tt>CleanFaxData</tt>,

        <tt>ConsecutiveBadFaxLines</tt>,

        <tt>DateTime</tt>,

        <tt>DocumentName</tt>,

        <tt>ImageDescription</tt>,

        <tt>Orientation</tt>

      Class S for separated images

      <tt>SamplesPerPixel</tt> = 4

        <tt>PlanarConfiguration</tt> = 1, 2

        <tt>Compression</tt> = 1 (none), 5 (LZW)

        <tt>PhotometricInterpretation</tt> = 5 (Separated)

        <tt>InkSet</tt> = 1 (CMYK)

        <tt>DotRange</tt>,

        <tt>InkNames</tt>,

        <tt>DotRange</tt>,

        <tt>TargetPrinter</tt>

      Class Y for YCbCr images

      <tt>SamplesPerPixel</tt> = 3

        <tt>BitsPerSample</tt> = <8,8,8>

        <tt>PlanarConfiguration</tt> = 1, 2

        <tt>Compression</tt> = 1 (none),  5 (LZW), 7 (JPEG)

        <tt>PhotometricInterpretation</tt> = 6 (YCbCr)

        <tt>YCbCrCoefficients</tt>,

        <tt>YCbCrSubsampling</tt>,

        <tt>YCbCrPositioning</tt>

        (colorimetry info from Appendix H; see above)

      Class "JPEG" for JPEG images (per TTN2)

      <tt>PhotometricInterpretation</tt> = 1 (grayscale), 2 (RGB), 5 (CMYK), 6 (YCbCr)

        (Class Y tags if YCbCr)

        (Class S tags if CMYK)

        <tt>Compression</tt> = 7 (JPEG)

    In addition, the library supports some optional compression algorithms

    that are, in some cases, of dubious value.

    Compression tag valueCompression algorithm

    32766NeXT 2-bit encoding

    32809ThunderScan 4-bit encoding

    32909Pixar companded 11-bit ZIP encoding

    32946PKZIP-style Deflate encoding (experimental)

    34676SGI 32-bit Log Luminance encoding (experimental)

    34677SGI 24-bit Log Luminance encoding (experimental)

    Note that there is no support for the JPEG-related tags defined

    in the 6.0 specification; the JPEG support is based on the post-6.0

    proposal given in TIFF Technical Note #2.

      For more information on the experimental Log Luminance encoding

        consult the materials available at

        http://www.anyhere.com/gward/pixformat/tiffluv.html.

    The following table shows the tags that are recognized

    and how they are used by the library.  If no use is indicated,

    then the library reads and writes the tag, but does not use it internally.

      Tag Name

      Value

      R/W

      Library's Use (Comments)

      <tt>NewSubFileType</tt>

      254

      R/W

      none (called <tt>SubFileType</tt> in <tiff.h>)

      <tt>SubFileType</tt>

      255

      R/W

      none (called <tt>OSubFileType</tt> in <tiff.h>)

      <tt>ImageWidth</tt>

      256

      R/W

      lots

      <tt>ImageLength</tt>

      257

      R/W

      lots

      <tt>BitsPerSample</tt>

      258

      R/W

      lots

      <tt>Compression</tt>

      259

      R/W

      to select appropriate codec

      <tt>PhotometricInterpretation</tt>

      262

      R/W

      lots

      <tt>Thresholding</tt>

      263

      R/W

      <tt>CellWidth</tt>

      264

      parsed but ignored

      <tt>CellLength</tt>

      265

      parsed but ignored

      <tt>FillOrder</tt>

      266

      R/W

      control bit order

      <tt>DocumentName</tt>

      269

      R/W

      <tt>ImageDescription</tt>

      270

      R/W

      <tt>Make</tt>

      271

      R/W

      <tt>Model</tt>

      272

      R/W

      <tt>StripOffsets</tt>

      273

      R/W

      data i/o

      <tt>Orientation</tt>

      274

      R/W

      <tt>SamplesPerPixel</tt>

      277

      R/W

      lots

      <tt>RowsPerStrip</tt>

      278

      R/W

      data i/o

    <tt>StripByteCounts</tt>

      279

      R/W

      data i/o

      <tt>MinSampleValue</tt>

      280

      R/W

      <tt>MaxSampleValue</tt>

      281

      R/W

      <tt>XResolution</tt>

      282

      R/W

      <tt>YResolution</tt>

      283

      R/W

      used by Group 3 2d encoder

      <tt>PlanarConfiguration</tt>

      284

      R/W

      data i/o

      <tt>PageName</tt>

      285

      R/W

      <tt>XPosition</tt>

      286

      R/W

      <tt>YPosition</tt>

      286

      R/W

      <tt>FreeOffsets</tt>

      288

      parsed but ignored

      <tt>FreeByteCounts</tt>

      289

      parsed but ignored

      <tt>GrayResponseUnit</tt>

      290

      parsed but ignored

      <tt>GrayResponseCurve</tt>

      291

      parsed but ignored

      <tt>Group3Options</tt>

      292

      R/W

      used by Group 3 codec

      <tt>Group4Options</tt>

      293

      R/W

      <tt>ResolutionUnit</tt>

      296

      R/W

      used by Group 3 2d encoder

      <tt>PageNumber</tt>

      297

      R/W

      <tt>ColorResponseUnit</tt>

      300

      parsed but ignored

      <tt>TransferFunction</tt>

      301

      R/W

      <tt>Software</tt>

      305

      R/W

      <tt>DateTime</tt>

      306

      R/W

      <tt>Artist</tt>

      315

      R/W

      <tt>HostComputer</tt>

      316

      R/W

      <tt>Predictor</tt>

      317

      R/W

      used by LZW codec

      <tt>WhitePoint</tt>

      318

      R/W

      <tt>PrimaryChromacities</tt>

      319

      R/W

      <tt>ColorMap</tt>

      320

      R/W

      <tt>TileWidth</tt>

      322

      R/W

      data i/o

      <tt>TileLength</tt>

      323

      R/W

      data i/o

      <tt>TileOffsets</tt>

      324

      R/W

      data i/o

      <tt>TileByteCounts</tt>

      324

      R/W

      data i/o

      <tt>BadFaxLines</tt>

      326

      R/W

      <tt>CleanFaxData</tt>

      327

      R/W

      <tt>ConsecutiveBadFaxLines</tt>

      328

      R/W

      <tt>SubIFD</tt>

      330

      R/W

      subimage descriptor support

      <tt>InkSet</tt>

      332

      R/W

      <tt>InkNames</tt>

      333

      R/W

      <tt>DotRange</tt>

      336

      R/W

      <tt>TargetPrinter</tt>

      337

      R/W

      <tt>ExtraSamples</tt>

      338

      R/W

      lots

      <tt>SampleFormat</tt>

      339

      R/W

      <tt>SMinSampleValue</tt>

      340

      R/W

      <tt>SMaxSampleValue</tt>

      341

      R/W

      <tt>JPEGTables</tt>

      347

      R/W

      used by JPEG codec

      <tt>YCbCrCoefficients</tt>

      529

      R/W

      used by <tt>TIFFReadRGBAImage</tt> support

      <tt>YCbCrSubsampling</tt>

      530

      R/W

      tile/strip size calculations

      <tt>YCbCrPositioning</tt>

      531

      R/W

      <tt>ReferenceBlackWhite</tt>

      532

      R/W

      <tt>Matteing</tt>

      32995

      R

      none (obsoleted by <tt>ExtraSamples</tt> tag)

      <tt>DataType</tt>

      32996

      R

      none (obsoleted by <tt>SampleFormat</tt> tag)

      <tt>ImageDepth</tt>

      32997

      R/W

      tile/strip calculations

      <tt>TileDepth</tt>

      32998

      R/W

      tile/strip calculations

      <tt>StoNits</tt>

      37439

      R/W

    The <tt>Matteing</tt> and <tt>DataType</tt>

    tags have been obsoleted by the 6.0

    <tt>ExtraSamples</tt> and <tt>SampleFormat</tt> tags.

    Consult the documentation on the

    <tt>ExtraSamples</tt> tag and Associated Alpha for elaboration.  Note however

    that if you use Associated Alpha, you are expected to save data that is

    pre-multipled by Alpha.  If this means nothing to you, check out

    Porter & Duff's paper in the '84 SIGGRAPH proceedings: "Compositing Digital

    Images".

    The <tt>ImageDepth</tt>

    tag is a non-standard, but registered tag that specifies

    the Z-dimension of volumetric data.  The combination of <tt>ImageWidth</tt>,

    <tt>ImageLength</tt>, and <tt>ImageDepth</tt>,

    defines a 3D volume of pixels that are

    further specified by <tt>BitsPerSample</tt> and

    <tt>SamplesPerPixel</tt>.  The <tt>TileDepth</tt>

    tag (also non-standard, but registered) can be used to specified a

    subvolume "tiling" of a volume of data.

    The Colorimetry, and CMYK tags are additions that appear in TIFF 6.0.

    Consult the TIFF 6.0 specification included in the doc directory

    and online.

    The JPEG-related tag is specified in

    TIFF Technical Note #2 which defines

    a revised JPEG-in-TIFF scheme (revised over that appendix that was

    part of the TIFF 6.0 specification).

    Last updated: $Date: 2005/12/28 06:53:18 $