Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!lll-winken!uunet!hite386!tlvx!sysop
From: sysop@tlvx.UUCP (SysOp)
Newsgroups: comp.sys.amiga
Subject: Re: Gif to IFF
Summary: GIF viewers for Amiga
Message-ID: <198@tlvx.UUCP>
Date: 23 Apr 89 01:24:32 GMT
References: <4330@alvin.mcnc.org> <6930@saturn.ucsc.edu> <3310@eos.UUCP>
Organization: Temporal Vortex of Jacksonville, Florida
Lines: 66

In article <3310@eos.UUCP>, barry@eos.UUCP (Kenn Barry) writes:
> In article <6930@saturn.ucsc.edu> odin@ucscb.UCSC.EDU (Jon Granrose) writes:
> >In article <4330@alvin.mcnc.org> raw@mcnc.org (Russell Williams) writes:
> >>does anybody have a file to transfer GIF files to IFF so I can import
> >>them into Professional Page?
> >
> >	I don't think there actually is a program to do this.  I have looked
> >on Compuserve (the originator of the GIF protocol) and not been able to find
> >one.

There are a couple of programs which DISPLAY GIF files on Amiga.  I have
something called "HAMGIF" which does a reasonable job of displaying the 256
color pictures in HAM mode (although there's a bit of nasty color choices as
the HAM colors switch from dark to light).  It doesn't overscan.

[misc deleted]

> >Here are UCSC, we had a discussion in forum about GIF and how to get it
> >to IFF and settled on some GIF display combined with a screen grabber program.
> 
> 	Yep, that's how I do it.
> 
The doc file for GIFFY 2.0 (made by the same author as HAMGIF, Steve Bennett)
says IFF save will be in version 3.0 (his compuserve account: 70046,441 --
maybe you can contact him).  The doc file is dated 12/5/87.

I dug out HAMGIF and ScreenX to see if it was hard to convert GIF to IFF this
way.  It doesn't seem to me to be much harder than if the GIF viewer had IFF
Save built in.  (ScreenX is a REAL NICE utility.)  I read the file into
DigiPaint and verified that it actually worked.  Of course, ScreenX has
a print option too.

> >Why should this be necessary?  I am not a proficient Amiga programmer (I'm
> >still learning Unix) but I would not think it would be too hard of a program
> >to write.  It would definately make things easier on people who handle lots
> >of GIf images.  Any comments?
> 
> 	Just one: in what way would it be easier to have a GIF->IFF
> converter, than just using a GIF display program, and capturing the
> image? I don't see the advantage in ease of use. The only limitation

[misc deleted]

Question: do you do more than just look at GIF pictures?  When you convert
from GIF to IFF, you'll lose some information.  If you end up going back
and forth, I would think it'd degrade the quality.  Is this true?

If you do go all the way and write your own, how about these suggestions:
use overscan whenever possible (or at least make it an option), and for HAM
displays, provide some way to analyze the picture to pick the most "optimal"
non-HAM colors, so as to make light-to-dark transitions less messy.  (Instead
of "guessing", how about making 2 passes through the file, making a list of
needed colors, sort the list, then perhaps the average.... Am I making
sense? ;-)  Maybe all you'd need is GIF to IFF file conversion.  SuperView
makes a great display program, and uses overscan, and can be used after the
conversion.  (In other words, you might just concentrate on a file-to-file
conversion, and let other utilities do displaying and printing.)

[misc deleted]

> -  QQQCLC  -                                    Kenn Barry
> ---------------------------------------------------------------------------
> ELECTRIC AVENUE:			{most major sites}!ames!eos!barry
> ARPA:					barry@eos.arc.nasa.gov

Gary Wolfe ...!uunet!hite386!tlvx!sysop