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From: joko@crl.com (Joe Kohn)
Newsgroups: comp.binaries.apple2
Subject: Compare (desc)
Date: 17 Jan 1996 10:32:33 -0800
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A picture is worth 1,000 words!

In an attempt to present an accurate and objective representation of the
results of the various IIGS graphics conversion programs, I downloaded a
GIF file and then converted it using Convert 3200, Prism and
SuperConvert. The original graphic can be found at:

http://www.ksc.nasa.gov/images/launchpalms.gif

It's a NASA photo of a space shuttle lift-off. The GIF is 576 x 450 and
contains 256 colors. Since I wanted to be able to see the entire graphic,
I attempted to scale it down so that it would fit on one screen. Using
Convert 3200, that program automatically scales down all graphics to 320
x 200. With Prism, I chose the option "Reduce To Screen" and clicked on
the "Smooth Reduction" option. I also clicked on dithering. With
SuperConvert, I tried several different options, described below....


C3200.3200    |   With Convert 3200, I just simply loaded the graphic,
C3200.256     |   and clicked on the option to convert the graphic using
C3200.16      |   all the available formats, and then simply saved those
C3200.grey    |   to disk as 16, 256, 3200 and greyscale.

Prism.Grey    |   As noted above, these were "reduced to screen" with
Prism.16      |   smooth reduction and dithering toggled. They are
Prism.256     |   smaller in size...not quite 320 x 200.
Prism.3200    |

SC.Grey.diff  - The was created by using SuperConvert's error diffusion
                option and it was cropped to fit on one screen.

sc.16.closest - The was created by using SuperConvert's closest match
                option and it was cropped to fit on one screen.

Joe Kohn
Publisher, Shareware Solutions II
http://www.crl.com/~joko