tiff(3tcl)						      TIFF image manipulation							tiff(3tcl)

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NAME

       tiff - TIFF reading, writing, and querying and manipulation of meta data

SYNOPSIS

       package require Tcl  8.2

       package require tiff  ?0.2.1?

       ::tiff::isTIFF file

       ::tiff::byteOrder file

       ::tiff::numImages file

       ::tiff::dimensions file ?image?

       ::tiff::imageInfo file ?image?

       ::tiff::entries file ?image?

       ::tiff::getEntry file entry ?image?

       ::tiff::addEntry file entry ?image?

       ::tiff::deleteEntry file entry ?image?

       ::tiff::getImage file ?image?

       ::tiff::writeImage image file ?entry?

       ::tiff::nametotag names

       ::tiff::tagtoname tags

       ::tiff::debug file

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DESCRIPTION

       This  package  provides commands to query, modify, read, and write TIFF images.	TIFF stands for Tagged Image File Format and is a standard
       for lossless storage of photographical  images  and  associated	metadata.   It	is  specified  at  http://partners.adobe.com/public/devel-
       oper/tiff/index.html.

       Multiple  images  may  be stored in a single TIFF file. The ?image? options to the functions in this package are for accessing images other
       than the first. Data in a TIFF image is stored as a series of tags having a numerical value, which are represented  in  either  a  4  digit
       hexadecimal  format  or a string name. For a reference on defined tags and their meanings see http://www.awaresystems.be/imaging/tiff/tiff-
       tags.html

COMMANDS

       ::tiff::isTIFF file
	      Returns a boolean value indicating if file is a TIFF image.

       ::tiff::byteOrder file
	      Returns either big or little.  Throws an error if file is not a TIFF image.

       ::tiff::numImages file
	      Returns the number of images in file.  Throws an error if file is not a TIFF image.

       ::tiff::dimensions file ?image?
	      Returns the dimensions of image number ?image? in file as a list of the horizontal and vertical pixel count.   Throws  an  error	if
	      file is not a TIFF image.

       ::tiff::imageInfo file ?image?
	      Returns  a  dictionary  with  keys ImageWidth, ImageLength, BitsPerSample, Compression, PhotometricInterpretation, ImageDescription,
	      Orientation, XResolution, YResolution, ResolutionUnit, DateTime, Artist, and HostComputer. The values are the associated	properties
	      of the TIFF ?image? in file. Values may be empty if the associated tag is not present in the file.

		  puts [::tiff::imageInfo photo.tif]

		  ImageWidth 686 ImageLength 1024 BitsPerSample {8 8 8} Compression 1
		  PhotometricInterpretation 2 ImageDescription {} Orientation 1
		  XResolution 170.667 YResolution 170.667 ResolutionUnit 2 DateTime {2005:12:28 19:44:45}
		  Artist {} HostComputer {}

	      There is nothing special about these tags, this is simply a convience procedure which calls getEntry with common entries.  Throws an
	      error if file is not a TIFF image.

       ::tiff::entries file ?image?
	      Returns a list of all entries in the given file and ?image?  in hexadecimal format.  Throws an error if file is not a TIFF image.

       ::tiff::getEntry file entry ?image?
	      Returns the value of entry from image ?image? in the TIFF file.  entry may be a list of multiple	entries.  If  an  entry  does  not
	      exist, an empty string is returned

		  set data [::tiff::getEntry photo.tif {0131 0132}]
		  puts "file was written at [lindex $data 0] with software [lindex $data 1]"

	      Throws an error if file is not a TIFF image.

       ::tiff::addEntry file entry ?image?
	      Adds the specified entries to the image named by ?image? (default 0), or optionally all.	entry must be a list where each element is
	      a list of tag, type, and value. If a tag already exists, it is overwritten.

		  ::tiff::addEntry photo.tif {{010e 2 "an example photo"} {013b 2 "Aaron F"}}

	      The data types are defined as follows

	      1      BYTE (8 bit unsigned integer)

	      2      ASCII

	      3      SHORT (16 bit unsigned integer)

	      4      LONG (32 bit unsigned integer)

	      5      RATIONAL

	      6      SBYTE (8 bit signed byte)

	      7      UNDEFINED (uninterpreted binary data)

	      8      SSHORT (signed 16 bit integer)

	      9      SLONG (signed 32 bit integer)

	      10     SRATIONAL

	      11     FLOAT (32 bit floating point number)

	      12     DOUBLE (64 bit floating point number)

	      Throws an error if file is not a TIFF image.

       ::tiff::deleteEntry file entry ?image?
	      Deletes the specified entries from the image named by ?image? (default 0), or optionally all.  Throws an error if file is not a TIFF
	      image.

       ::tiff::getImage file ?image?
	      Returns  the  name  of a Tk image containing the image at index ?image? from file Throws an error if file is not a TIFF image, or if
	      image is an unsupported format.  Supported formats are uncompressed 24 bit RGB and uncompressed 8 bit palette.

       ::tiff::writeImage image file ?entry?
	      Writes the contents of the Tk image image to a tiff file file. Files are written in the 24 bit uncompressed format, with big  endian
	      byte order. Additional entries to be added to the image may be specified, in the same format as tiff::addEntry

       ::tiff::nametotag names
	      Returns a list with names translated from string to 4 digit format. 4 digit names in the input are passed through unchanged. Strings
	      without a defined tag name will throw an error.

       ::tiff::tagtoname tags
	      Returns a list with tags translated from 4 digit to string format. If a tag does not have  a  defined  name  it  is  passed  through
	      unchanged.

       ::tiff::debug file
	      Prints everything we know about the given file in a nice format.

VARIABLES

       The mapping of 4 digit tag names to string names uses the array ::tiff::tiff_tags. The reverse mapping uses the array ::tiff::tiff_sgat.

LIMITATIONS

       [1]    Cannot write exif ifd

       [2]    Reading limited to uncompressed 8 bit rgb and 8 bit palletized images

       [3]    Writing limited to uncompressed 8 bit rgb

BUGS, IDEAS, FEEDBACK
       This  document, and the package it describes, will undoubtedly contain bugs and other problems.	Please report such in the category tiff of
       the Tcllib SF Trackers [http://sourceforge.net/tracker/?group_id=12883].  Please also report any ideas for enhancements you  may  have  for
       either package and/or documentation.

KEYWORDS

       image, tif, tiff

CATEGORY

       File formats

COPYRIGHT

       Copyright (c) 2005-2006, Aaron Faupell <afaupell@users.sourceforge.net>

tiff								       0.2.1								tiff(3tcl)