Amiga Image ViewEr
                              version 1.5
                               March 1994

Role : Displaying 256 colors pictures on a basic Amiga .
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Copyright :
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   AIVE is (c) 1994 Laurent Vivier . It may not be sold in commercial goal
without my written approval . It can't be distributed for a fee which exceed
of 15 French Francs (3 dollars) . It is forbidden to make a profit through
the distribution of this software without my written approval .
   It can't be distributed without its documentations . Thus, Files "AIVE",
"AIVE.docF", "AIVE.docE" can't be split .

   This software is freeware . You can contact me for help or any question,
suggestions . (or to correct this document, to speak english is a nightmare
for me)

Disclaimer :
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   I accept no responsability for the use or misuse of this software, and
for dammage it could produce. Use at your own risks .

Contact :
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   postal address :

            Laurent Vivier
            Avenue Général De Gaulle
            38380 Saint Laurent du Pont
            FRANCE

   e-mail :
         Laurent.Vivier@ufrima.imag.fr (until june 1994)
         vivier@isis.imag.fr (until june 1994)

Supported formats : GIF87a, GIF89a (interlaced or not), IFF .
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The Graphic Interchange Format(c) is the Copyright property of
CompuServe Incorporated. GIF(sm) is a Service Mark property of
CompuServe Incorporated.

Use :
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   We can use AIVE only from CLI (or Shell) . We give file name and options
from parameters command line .

Supported options :
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   AIVE writes possible options if we run it without parameters !
All parameters must be written in lower case .

AIVE name [hire|lore|ehb][nolace][grey][scale]
          [width w][heighth][ratio a/b][color #colors]

HIRE,LORE,EHB : to choose graphic mode to use
   HIRE : high resolution
   LORE : low resolution
   EHB  : Extra-Half-Bright
the default mode is HAM .

NOLACE : by default it uses interlaced mode, this option disables it .

GREY : to display picture in grey levels (16 colors, HIRE)

COLOR n : n is the number of colors tu use (>= 8, default is the maximum).
          With the option GREY, n is the number of grey levels .

SCALE   : the size of the picture is modified to fit in the screen .

WIDTH w : w is the maximum width of the screen

HEIGHT h : h is the maximum height of the screen

RATIO a/b : bending ratio of the screen : x is the width of a pixel, y the
            height, then : y = x * (a/b) .
            default : a/b = 1/2 LORE (= HAM, EHB)
                          = 1/1 LORE and NOLACE
                          = 1/1 HIRE
                          = 2/1 HIRE and NOLACE
            that values are not best . But they are dependant on your
            screen . Compute them .

Interface :
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   When we run AIVE, a window is opened . We find in the name of the
picture, its kind (GIF87a, GIF89a, IFF ...), its size, and the progression
of the decoding . A gadget "Stop" permits us to stop the operation, and to
quit the program . The keyboard shortcut is "ESC", it's enable only if the
window is activated (and then, not the screen where is the picture !) .

Note : Under OS2.0, you can display picture bigger than your screen . To
move it use the standard system operation : Left Amiga - Left Mouse Key and
move mouse to move picture . Under OS1.3, picture is automaticaly fitted
in the screen .

Technical :
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   AIVE uses Floyd-Steinberg dithering, CIE luminance weight, and custom
algorithms, and no floating point operations . For more details, refer to
"AIVE.docF" (it's time to learn French ! All my apologies)

Possible evolutions :
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   - to run from Workbench
   - gamma correction (why ?)
   - a printer option
   - a save option
   - PCX and BMP formats, perhaps JPEG (I don't think !)
   - a better human-computer interface under intuition

Compatibility :
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   AIVE was developed under OS1.2, then OS2.0 . It may be run under all
systems .
   We can meet problem with graphic cards : I don't use the "WritePixel"
function from "graphics.library", but I write the value in memory .

   The test activity was made on my A500 :
   mother board rev 5a, OS2.0, 2 drives DDDS, 512 FAST, 512 CHIP .

Thanks to :
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   Frederic Elisei   Archimede user of genius, who inspires me
   Franck Lyonnet    Idem
                     Look at their JPEG viewers for Acorn Archimede 5000,
                     speedy than all GIF viewer on Amiga (500 !) .
   Roger Wilson      who written a paper on his software ChangeFSI .
   Steven A. Bennet  author of GIF decoder which inspirates me .
   Cindy Crowford    to her beautiful body (a good motivation !) .

   UFR Informatique  where I have discovered the internet world .
   et mathematiques  (Thanks to system administrators)
   appliquees de     Come studying in Grenoble
   Grenoble          (the country is beautiful : its ski resorts, its lakes)

History
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January 1994   version 1.0    First release
January 1994   version 1.2    corrects 2 little bugs :
                              - System alert with an odd picture width
                              - little dithering saturation
March 1994     version 1.5    Corrects other bugs :
                              - system alert when using grey and low
                                resolution at the same time
                              - impossibility to made grey levels with less
                                than 16 levels .
                              Evolution :
                              - Optimizing of dithering (close to 2 or 3)
                              - scaling

Author : Laurent Vivier
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