Author ritter@earthlink.net (Niles Ritter)
Limitations: There are no provisions in TIFF for storing vector graphics, text annotation, etc (although such items could be easily constructed using TIFF extensions), and so if this is a requirement you would be better off with a format with broader scope, such as PostScript, CGM, or PICT. TIFF is based on file-offsets, so that it is not easily "streamable" in the way JPEG JFIF streams are.
A common complaint of TIFF is rooted in its flexibility. For example the TIFF format permits both MSB ("Motorola") and LSB ("Intel") byte order data to be stored, with a header item indicating which order is used. There are old, poorly written TIFF programs on the PC which rebelled against this and assume that all TIFF files are Intel byte order. It is very easy to write a TIFF-writer, but very difficult to write a fully TIFF compliant reader.
TIFF uses 4-byte integer file offsets to store image data, with the consequence that a TIFF file cannot have more than 4 Gigabytes of raster data (and some files have begun to approach this boundary). However, this is 4G of compressed data, and so if the compression ratio is high enough, theoretically a TIFF image could be much larger (in fact, 2**32-1 pixels square).
Strengths: TIFF is primarily designed for raster data interchange. It's main strengths are a highly flexible and platform-independent format which is supported by numerous image processing applications. Since it was designed by developers of printers, scanners and monitors, it has a very rich space of information elements for colorimetry calibration, gamut tables, etc. Such information is also very useful for remote sensing and multispectral applications.
Another feature of TIFF which is also useful is the ability to decompose an image by tiles rather than scanlines. This permits much more efficient access to very large imagery which has been compressed (since one does not have to decompress an entire scanline).
Theoretically, TIFF can support imagery with multiple bands (up to 64K bands), arbitrary # bits per pixel, data cubes, and multiple images per file, including thumbnail subsampled images.
Color spaces supported include
TIFF is a trademark, formerly registered to Aldus, and which is now claimed (though not yet registered) by Adobe Systems, Inc.
TIFF tag and TIFF compression ID registration is handled by Adobe Developer Relations. Please send your requests to Adobe developer relations support staff at:
gapdevsup@adobe.com
Adobe needs the following information to assign a TIFF tag or compression code:
Company Name: Contact Name: Address: Phone: Fax: Email: Brief description of tag format (optional, see below):It is their policy not to divulge information about TIFF tag owners or the format of private tag data without the owner's consent. If you wish to make public the fact that you are the owner of a tag and/or details about a tag's layout, you can send them this information and they will store it in their TIFF registration database.
To: tiff-request@olympiakos.com
Subject: none
subscribe tiff
(optionally, after "subscribe tiff" you may place an email address).
You will receive a confirmation from the Majordomo listserver running
there. To post messages, send email to
tiff@olympiakos.com.
There is also a mailing list for discussing the GeoTIFF TIFF tag extensions for georeferenced raster data, which can be accessed by sending email:
To: geotiff-request@mtmorrison.jpl.nasa.gov
Subject: none
subscribe geotiff Your-Name-Here
An archive.
of the ongoing GeoTIFF list discussion is now available.
A compressed PostScript version of the spec is available from the SGI TIFF archive, which also has an uncompressed version.
Older Revision Specs are also online (for historians, only!):
See also the "Extensions" section on the
freeware "Zip-in-TIFF" alternative proposed.
The
LIBTIFF.ORG Page for the libtiff package is here.
Unix-style
manual pages for the suboutines and utilities are also now online.
There is a hacked version of Libtiff for Windows-flavored compilers,
allowing the creation of DLL's, and is called
LIBTIFFW. The cognizant programmer is
Soren Pingel Dalsgaard.
XV Viewer by John
Bradley is a very nice display program, which has some nice
editing features, and a "Visual Schauzer" which provides a
icon/desktop view of a directory, with thumbnails, etc. Note,
however, that the most recent versions are *NOT* public domain,
but must be licensed. The source code is also available, and
it uses the "libtiff" package.
See also the
Unix and X-windows
entry of the comp.graphics FAQ archive.
There are a lot of TIFF programs in the
SimTel archives:
On a related note, see also the
PNG (Portable Network Graphics) Web page, for another
format using Zip and zlib.
Caveat: the Zip-TIFF approach has not been adopted widely, as yet.
However, Adobe technical support has expressed the intention to
include it in the next TIFF 7.0 specification (to be released
Real Soon Now (TM)).
See also the
Facsimile (Fax) SubSection
of the
WWW Virtual Library for more information.
TIFF Fax Viewers are available at:
Note: TIFF/IT = Transport Independent File Format for Image Technology.
It is intended that the TIFF/IT standard will reduce the variation between
TIFF implementations which has led to a reputation of valid TIFF files
often being unreadable when transferred between
different applications.
The TIFF/IT spec is available from the ANSI standards organization or
NPES, the association of suppliers of printing and publishing
technologies. It is ANSI standard IT8.8-1993 'Tag image format for image
technology' NPES's phone number in the United States is (703) 264-7200.
RFC 1314 concerns suggested standards for using TIFF for
document interchange on the Internet. The standard is compared
with the "TIFF Class F" fax scheme.
TIFF Online Test Images. If you have a TIFF viewer linked
to your Web Browser, you can test it on these images. Sources
for TIFF viewers is also provided.
What programs can read Multi-page TIFF?
Here are some programs that have been used by readers of the TIFF
mailing list:
Is the LZW Compression in TIFF patented?
Yep;
Unisys holds a patent on the compression algorithm, which is
the same as the one used in Compuserve's GIF format. For more
information, see the
Graphics File Format FAQ entry, which has further details and
pointers to the patents and licensing agreements.
Where can I find Public TIFF Software ?
TIFF Libraries and Source Code
LIBTIFF
Sam Leffler has written a
platform-independent, public-domain
subroutine library and tool-set for TIFF files, called "libtiff".
LIBTIFF
TIFF256 Graphics Library is a shareware, licensable TIFF library
supporting TIFF 5.0 (the latest rev is 6.0). Don't know much about it.
WOCAR: Optical Character Recognition (OCR) for TIFF
WOCAR is an Optical Characters Recognition Application (OCR). It
converts scanned documents to text documents. The software can process
documents written in English or in French. WOCAR can work with any
scanner that supports the TWAIN interface. It can also process any
bilevel TIFF image file. (multipage TIFF files are supported)
This application works on Windows 95 and Windows NT, and is also
availabe at the
Simtelnet FTP site. The author of this package is
Cyril Cambien, who also
has his own web page.
ImTool package
The ImTools
converter put out by the San Diego Supercomputer Center claims to
be able to handle "many tiff formats that others can't". Try it
out and let me know.
SimTel package
SimTel TIFF package Software, source code, etc available,
primarily for MS-DOS platforms. It includes the original TIFF
library put out by Aldus, and looks to be rather outdated,
and unlikely to support TIFF 6.0 additions, such as tiling.
Comp.Graphics Archives
The
Usenet Comp.Graphics FAQ files is an excellent resource for finding
TIFF viewers, converters, etc. Discussions
arising in the comp.graphics.* newsgroups about pros and cons for
other formats, the "LZW" patent issues, etc are also included.
In particular the section on
Image Conversion and Display programs is very useful.
Most of the references below are extracted from this reference.
Viewers and Editors
Macintosh
One of the best public-domain TIFF viewers for the mac is also
a very nice image-processing system in its own right, called
NIH Image. It now supports Adobe Photoshop plug-ins as well,
and can display most garden-variety TIFF files, though older
versions had problems with "tiled" TIFF images. And yes, it will
handle 16-bit grayscale TIFF, if need be. It is limited to
8-bit color display, but given a 24-bit RGB it will allow you
to edit the color planes separately, and view "palettized"
version of the color data. Pascal Source code for Metrowerks
CW7 or later is also available for hacking.
Unix Boxes/X
ImageMagick can open most TIFF files, and do some annotation,
using the standard X-window interface. It is in the public domain.
PC/DOS/Windows Flavored Systems
I don't have any personal experience with these systems, but your
best bet is to refer to the
MS-DOS Image Viewers or the
Windows and OS/2
entries of the comp.graphics FAQ archives. Note, however, that some of
the links are out of date.
What TIFF Extensions are Available?
TIFF is a very extensible format, and there are a number of efforts to
extend TIFF for specific applications by registering new tags
with Adobe. A number of such extensions are described below:
GeoTIFF
GeoTIFF is a newly emerging interchange standard,
which permits the addition of Geographic information
such as projections, datums, etc, associated with remote sensing or
cartographic raster data.
Adobe Extensions for PageMaker
Adobe has recently defined a set of
extensions
to the TIFF spec, allowing for "clipping-path" definitions,
etc.
JPEG - in - TIFF
Another effort involves the encapsulation of a decent lossy JPEG
stream within TIFF; the original 6.0 spec was not worked out
correctly. Tom Lane led the development of the new TIFF implementation
called
JPEG-in-TIFF.
The current libtiff package
offers some level of JPEG support, when linked with the IJG
JPEG library, available at
ftp.uu.net
(if you can ever get in), or at
ftp.cs.wisc.edu.
See also Tom Lane's
JPEG Frequently Asked Questions file.
Zip - in - TIFF
The best lossless compression scheme in TIFF currently is
LZW (Lempel Ziv Welch), which, unfortunately, suffers from
the same
Unisys patent problems as the popular "GIF" format.
For this reason, an alternative, non-proprietary compression
scheme has been proposed, based on the
ZLIB/Deflation stream.
The current libtiff package
offers some level
of Zip support, when linked with the zlib library, available
at the
ftp.uu.net archives, the.
www-dsed.llnl.gov archives, and the
swrinde.nde.swri.edu archive (in Zip format).
The current version level is 1.0.4,
as of 21 November, 1996.
TIFF Class F Revised Specification
The
TIFF Class F Revised Specification
documents the TIFF spec tags specific to FAX applications.
RFC 804 covers the RFC on the
CCITT Recommendation T.4 which explains CCITT Group 3 encoding
and the Modified Huffman and Modified Read compression algorithms.
TIFF/IT Prepress Interchange Standard
The
Raster Graphic Interchange Standards
page has a link to information on
TIFF/IT standard for prepress applications.
TIFF enhancements for Adobe PageMaker 6.0
This
Technical Note
includes new TIFF tags for supporting
such things as TIFF directory "Trees" (as opposed to the
singly-linked list of IFD's), defining polygonal "clipping
paths" (ala PostScript), indexed ("palette") images for
other color spaces such as CMYK, and a definition of
the new ICC L*a*b* color space.
RichTIFF
The RichTIFF standard was defined by
Crosfield , now maintained by ITPC, and was designed
primarily for newsphoto interchange. RichTIFF is not really a standard
format, but rather a guideline on how to format TIFF files for this
purpose.
Wang TIFF Image-Annotation extensions
Wang has developed some tag extensions
for TIFF files, including post-it notes etc. It is very Wintel
specific, but you may find it useful.
Kodak TIFF extensions
Kodak has several file formats in use which are more or
less based on the TIFF spec (though not always complying with
the strict rules). The Kodak Professional Digital Camera System
produces a file with TIFF header and multiple IFD's of various
types, and there is also a "KIFF" (Kodak Image File Format) based
on TIFF with proprietary colorspace and compression methods
(the use of which changes their name to "KIC" - Kodak Image
Compression - files. For more information contact
Kodak directly.
Internet RFC's Related to TIFF
RFC 804 covers the RFC on the
CCITT Recommendation T.4 which explains CCITT Group 3 encoding
and the Modified Huffman and Modified Read compression algorithms.
(Group 4 is detailed in CCITT Recommendation T.6).
Other TIFF Related Pages
Last modified: Feb 14, 1997
Comments? e-mail
ritter@earthlink.net (Niles Ritter)