TIFF_Files.txt
==============

LIBTIFF is the C library for handling TIFF files, by Sam Leffler of Silicon
Graphics. I have completed the Acorn port of this library, and have uploaded
it here. I am:

	Peter Greenham
	peter@enlarion.demon.co.uk


Files:

tiff-v3.4beta024.tar.gz
=======================
This is the full LIBTIFF distribution source archive. It is not
Acorn-specific, but the Acorn port files are included, as well as those for
various other platforms. Also included here is full documentation in html
format. ArcWeb is quite happy reading these locally, but you will want to set
the filetype first I expect.

There are lots of long filenames in here. Have fun!

You might prefer to download this one than the one on sgi's ftp server, as
the latter tends to grind to a halt when accessed from here. If you *must*
get it from ftp.sgi.com, use BatchFTP.

Also, the current archive on ftp.sgi.com is missing some of the Acorn port
files included here. Simple omission which will be rectified shortly anyway.

LIBTIFF-v3.4beta024.spk
=======================
This is the extracted Acorn version of LIBTIFF. This is what is produced by
running the contrib.acorn.install script supplied in the first file. However,
as that procedure is a little fraught (mostly because Acorn haven't figured
out that long filenames are a Good Thing), I have included this archive. This
contains the source files sorted into an Acorn C style directory structure,
with the makefile. You should just need to extract the LIBTIFF directory, run
SetVars, and run Makefile.

tiffin_200.spk
==============
This is version 2.00 of Tiffin, an application written using LIBTIFF, which
translates images between sprites and TIFFs. Drop a tiff on it, you can save
a sprite, drop a sprite, save a tiff. It's that simple. It also allows batch
operation, for processing entire directories of images. This application, and
my port effort on LIBTIFF itself, was started because no available Acorn
software could cope with some fairly common TIFFs. ie: those exported by
PhotoShop 3.0. In addition, TIFF creation under RISC OS was being fraught,
with Creator giving problems and PhotoDesk not allowing compression.

This application is much enhanced over the previous version uploaded here. It
now loads the image into a window (handling multiple images as far as memory
allows).

In TIFF to Sprite conversion, Tiffin always creates a 32-bit sprite,
faithfully reproducing the quality of the original TIFF image. This is the
primary reason why it is only compatible with RISC OS 3.50 or later (though
another reason is the use of Dynamic Areas). You can, of course, use
ChangeFSI to take the resulting images down to other scales/depths.

In Sprite to TIFF conversion, it allows LZW compression (optionally), and a
choice between 24-bit and 32-bit RGB format. 24-bit is readable by ChangeFSI,
whereas 32-bit isn't. 32-bit is valid, however and Tiffin, and other
applications (such as PhotoShop) are quite happy with them.

NB: 32-bit sprite to 32-bit TIFF is the fastest conversion in this direction,
as it can just dump the data from the sprite's pixel raster rather than
having to process it to get RGB data.

NB: Tiffin is programmed using Acorn's Toolbox. When first run, Tiffin will
automatically update your !System if necessary (unless you've been playing
silly games with datestamps - it only copies its versions if they're newer
than the ones already in !System). This is done in the !Run file so it's easy
to comment out if you really object. I wouldn't bother though, it's quite
safe.

To do:
Allow creation of 32-bit CMYK TIFFs (useful for DTP work), and Index-Coloured
TIFFs direct from 1,2,4,8-bit sprites (which will make processing them
considerably faster). Also allow proper setting of picture resolution.
Possibly allow interactive access to all TIFF tags used in an image.

Misty.tif
=========
This file and others like it were the source of all the problems! Created
under KPT Bryce on a Power Macintosh and converted to TIFF by PhotoShop 3.0
(with no extra image-processing); ChangeFSI, PhotoDesk and
Impression/ArtWorks could make no sense of it. It's all down to Alpha
Channels, apparently.

Tiffin reads this fine, as well as just about every other TIFF thrown at it
(a couple of the very esoteric LIBTIFF test files fail).