Message-Id: <199707231815.LAA42444@dns.ccit.arizona.edu> Date: Wed, 23 Jul 1997 11:12:15 +0000 From: "Louis H. Sharpe II" <mailto:lsharpe@PICTUREL.COM> Subject: Re: TIFF Tag editor To: mailto:IMAGELIB@LISTSERV.ARIZONA.EDU
Norbert Lossau <mailto:lossau@MAIL.SUB.UNI-GOETTINGEN.DE> wrote:>We will have a great quantity of TIFFs and want to index the
>TIFF-header, e.g. the ASCII-fields "ImageDescription", "PageName".
>
>Our aim is to use informations in this fields for further automatic
>processes to restructure digitised documents.
>
>Has anyone heard about such a (possibly free) Editor?
1. We have found (but have not used) tifftag.exe, a Windows GUI-style tag editor. It is in the public domain and was written at Ralip in Sweden. An Altavista search shows it at:
http://nic.zcu.cz/ftp/packages/winsite-winnt/desktop/tifftag.zip
2. For batch processing, by far the best approach is to build your own program (assuming C language skills) from the utility tiffcp which ships in source code with the multi-platform libtiff library written by Sam Leffler at Silicon Graphics. Note that compiling this to create a runnable program is a job for a very good Unix programmer, so please don't bug Sam or the list unless you are one! The important thing about libtiff is that it generates correct TIFF files and can read virtually all the interesting flavors of correct TIFF files. This is not true of many programs. The source code to the library (not a utility, not a runnable program) is at:
ftp://ftp.sgi.com/graphics/tiff/
3. Image Alchemy, our favorite commercial (but inexpensive) batch image processing package (http://www.handmadesw.com) has the ability to jam some of the parameters of an image file (which are embodied as tags in a TIFF file), though I don't know specifically about the fields you mention. They have a technical support mailing list, or you can call Hap to find out.
4. It has been said (perhaps on this list) that it is a violation of basic (computer science) data integrity principles to store data in more than one place, since updating does not always get performed in all places. For example, TIFF editors may be able to modify some of the properties of the file you create, but likely will not know the semantics you used in those text fields. Thus when the editor makes modifications, it will not update your field (it can at best copy it over). This is a potential integrity problem, depending on what type of information you placed there. A better policy is to treat the TIFF file as an object and manage it externally in an object repository or object database.
Unfortunately, databases are another computer science problem, and libraries have little money for programmers. This was illustrated well by the protracted, meandering discussion this list had on the topic a short while ago.
5. Adobe is still working on TIFF version 7.0. It is clear that TIFF will continue to have less, not more, document-type features. Adobe (who controls both standards) sees more strategic advantage (and to be fair, perhaps more technical rigor) in placing such features into the Portable Document Format (PDF) instead.
While TIFF continues to be the better choice for (non-JPEG) archival materials, keeping such TIFF files as close to "baseline" (see the tiff spec) as possible is key to their being usable in future times.
7. JPEG (or the slightly richer and compatible JFIF) files are best not stored inside TIFF 6.0 files today, but rather as stand-alone files. TIFF 7.0 will allow that to be done "properly" (see TIFF Technical Note #2 at http://www.picturel.com/docs.html or at ftp://ftp.sgi.com/graphics/tiff/TTN2.draft.txt).
If you wish a similar capability for commenting JPEG files, we have located two utilities, but only on the Mac. The JPEG comment field can be up to 64,000 bytes long, suitable for the most egregious data integrity abuses :)
begin inserted text ---------------------------------------------------- got this at: http://liquefy.isca.uiowa.edu/mac/infomac/gst/grf/00grf-abstracts.txt
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#### BINHEX add-jfif-comment-102.hqx ****
From: Victor Tan <mailto:victort@extro.ucc.su.OZ.AU> Subject: addJFIFcomment 1.0.2
Hello everyone,
this is version 1.0.2 of addJFIFcomment, a bare bones utility that lets you add text comments to JFIF/JPEG files.
REQUIREMENTS: This program works on all Macs and PowerMacs. System 7.0 or later is required.
addJFIFcomment 1.0.2 is freeware.
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From: mailto:Francois.Pottier@inria.fr (Francois Pottier) Subject: Edit JFIF Comment 1.0.3
Edit JFIF Comment lets you view and modify the textual comments included in JFIF files (more commonly known as JPEG files). Doing so doesn't modify the compressed image data, which means that the tool is quick and lossless. Besides, it is scriptable, so it can be used to modify many files at once.
Version 1.0.3 allows entering special characters (such as carriage returns) in the comment.
Edit JFIF Comment is freeware. I am the author.
Francois Pottier mailto:Francois.Pottier@inria.fr http://pauillac.inria.fr/~fpottier/
end inserted text -----------------------------------------------------
Hope this helps!
Lou
Louis H. Sharpe II mailto:lsharpe@picturel.com Picture Elements, Inc. +1 303-444-6767 410 22nd Street, Boulder, CO 80302 USA fax +1 303-415-1392 http://www.picturel.com ftp://ftp.picturel.com/pub/incoming