Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!umich!samsung!usc!apple!uokmax!drtiller From: drtiller@uokmax.uucp (Donald Richard Tillery Jr) Newsgroups: comp.sys.amiga Subject: Re: GIF viewing again and again (long but informative!) Keywords: GIF, graphics, IFF, conversion Message-ID: <1990Aug23.045556.17590@uokmax.uucp> Date: 23 Aug 90 04:55:56 GMT References: <5338@harrier.ukc.ac.uk> Organization: Engineering Computer Network, University of Oklahoma, Norman, OK Lines: 71 I have had some experience in the area of GIF conversion and the following are some of my ramblings: The best (all this is in my own humble opinion) single-step converter is SHAMSharp. It will take a GIF and convert it to HAM (or SHAM if requested, but not in overscan mode) and will even do overscan. I haven't used it too extensively so I'm not sure whether it automatically scales a picture to the maximum overscan or not (although an earlier version - HAMSharp - would produce a blank picture when the GIF was too big). More versatile is GIFtoRGB V1.1 which allows the conversion of a GIF to an RGB file in the format of Digi View 4.0. The file may then be scaled and/or padded to a standard Amiga size and loaded into Digi View for conversion to any mode your heart desires, including Dynamic HAM and Dynamic Hi-Res. The RGB files are NOT compressed (their format isn't that is) so can be VERY large (in some cases over 1 Meg for an 800x600 or larger GIF). NOTE: Major drawback: NewTek will not sell the Digi View 4.0 software outright by itself. It is possible, however to tell them you want to "upgrade" to DV4.0 and you can purchase the software that way. This was suggested by someone at NewTek so no flames please. There are two commercial products which will allow decent GIF-IFF conversion but I've only had experience with one of them (I just read about the other one moments ago and at a list price of $199 I didn't really care what it was called). The Art Department (with _optional_ GIF module) will allow the intuitive loading and manipulating of a GIF picture (as well as RGB formats from Turbo Silver {I ray trace and go to a dynamic mode} the Sculpt series, Digi View 3.0 and Digi View 4.0) and saving it in any mode including Dynamic work-alikes of the NewTek versions (which are viewable with Dyna-Show although the version of TAD that I have doesn't work too well in this area, the files must be actually loaded into Digi View 4.0 and then re-saved for Dyna-Show to be able to read them). You can adjust all kinds of things with TAD including scaling, palette, contrast, brightness, gamma (a logarithmic intensity function), and even do color separation. It's not a bad program BUT the price is still too high ($50 or so for TAD and $30 or so for the GIF module) and the kick-in-the-head is that they offer a "professional" version at $199 list that will save to all the modes but also requires the external modules (at similar extra cost) to address GIF and the other optionals. I cry "FOUL" and call that a rip-off (no flames please, just IMHO). EXTREMELY PERTINANT NOTE: ALL these programs can require LARGE amounts of memory and computation time. TAD requires a large contiguous chunk of memory and it TAKES as much as there is (no multi-tasking here unless you run the other task first). The smaller that chunk, the more limited TAD becomes quite quickly. The computation time is the result of the difference in display types (obviously, but maybe not as evident:) and the fact that GIFs are compressed with the LZW algorithm (as used in lharc and I belive PKZip). If your machine is slow with these archivers (and they are if you run a 68000) then expect the translation time to be several times as slow in GIF conversion. HAMGIF is so quick (relatively - I use it for quick and dirty viewing before conversion) because there is almost no optimization done on the palette (which means the whole picture doesn't need to be loaded in thus reducing memory requirements) when converting to HAM. I personally use a GVP 68030 @ 28Mhz with 4megs Fast and 1 meg Chip and have over 120 Megs of HD and a SyQuest to store all those GIFs, RGBs, and IFFs and have had little problem with memory (some fragmentation if too may progs are run before TAD and it doesn't get a big enough contig chunk). I have had no conversion take more than a minute with any of the converters I've tried. If you don't have these resources, then you realize what you are facing in way of processing time and memory limitations. You can still convert, but stick with SHAMSharp and don't be impatient (that's what you have a multi- tasking machine for :-). _______ __________ _/____) ' __ /_/ / ' / / __ _ "N.I.N.J.A.J.I.S."-Me / \___/__/___/ |_ /__/__/__/_/_-_/__/_/ The Displaced Razorback. ___________________________________________/ Founder: IDGAFF Ltd. The Amiga Computer - "...a more fiendish disputant than the Great Hyperbolic Omni-Cognate Neutron Wrangler of Ciceronicus Twelve..." -D.Adams; Well, almost.