The Unofficial TIFF Home Page

Author ritter@earthlink.net (Niles Ritter)

Contents:

1. What is TIFF?
2. Should I use TIFF ?
3. Who owns TIFF?
4. How can I reserve my own tags/compression schemes?
5. Are there any TIFF mailing lists?
6. Where can I download the TIFF Specification?
7. What programs can read Multi-page TIFF?
8. Is the LZW compression in TIFF patented?
9. Where can I find Public TIFF Software ?
10. What TIFF Extensions are Available?
11. Other TIFF related Pages

What is TIFF ?

Should I use TIFF ?

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

• Grayscale
• Pseudocolor (any size)
• RGB
• YCbCr
• CMYK
• CIELab

• raw uncompressed,
• PackBits
• Lempel-Ziv-Welch (LZW)
• CCITT Fax 3 & 4
• JPEG (see below)

• 1-64 bit integer, signed or unsigned
• 32 or 64 bit IEEE floating point

Who owns TIFF?

TIFF is a trademark, formerly registered to Aldus, and which is now claimed (though not yet registered) by Adobe Systems, Inc.

How can I reserve my own tags/compression schemes?

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

Company Name:
Contact Name:
Address:
Phone:
Fax:
Email:
Brief description of tag format (optional, see below):

Are there any TIFF Mailing lists?

 	To: tiff-request@olympiakos.com
	Subject: none

        subscribe tiff

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

Where can I download the TIFF Specification?

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!):

Revision 4.0

Revision 5.0

What programs can read Multi-page TIFF?

• ViewFax (for X Windows)
• Hewlett Packard "imageview" (included with HP-UX)
• Northern Development Group "SwiftView" (multi-platform)
• Spicer "Imagenation" (multi-platform)
• TDF Corporation "Personal Image Edition" (Win & OS/2)
• TMS Sequoia (multi-platform)
• Microsoft/Wang "Imaging for Windows" (Win95 & WinNT)
• Crown Image
• Visioneer PaperPort (Win & Mac)
• Cerious ThumbsPlus (Win only)

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.

See also the "Extensions" section on the freeware "Zip-in-TIFF" alternative proposed.

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".

The LIBTIFF.ORG Page for the libtiff package is here.

Unix-style manual pages for the subroutines 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.

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.

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.

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.

There are a lot of TIFF programs in the SimTel archives:

• imagepro.zip basic image processing with TIFF, etc.
• Graphic Workshop can convert and display TIFF.

What TIFF Extensions are Available?

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.

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)).

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.

See also the Facsimile (Fax) SubSection of the WWW Virtual Library for more information.

TIFF Fax Viewers are available at:

• ftp.leo.org (look for "viewfax").

TIFF/IT Prepress Interchange Standard

The Raster Graphic Interchange Standards page has a link to information on TIFF/IT standard for prepress applications.

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.

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).

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.

Other TIFF Related Pages

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.