Short:    Univ. palette for 24-bit to 8-bit mass image-conv
Uploader: Björn Östberg <JetRacer@hem.passagen.se>
Author:   Björn Östberg <JetRacer@hem.passagen.se>
Type:     gfx/conv
Version:  1.21   99-05-27 (UL: 99-11-26)
Requires: AGA chipset

24to8pal v1.21 ©1999 SpEEd Productions / Björn Östberg

Commecial use without the permission of the author is strictly forbidden!

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Disclaimer: The programmer can't be held responsible for ANY damages caused
by this software - use it at your own risc!

No fee whatsoever can be charged for the archive nor it's contense -not even
for distrubution expences (Aminet have exclusive right to distribute this
archive and charge whatever fee they seem suitable). This archive must be
distributed in it's original shape without any modifications.
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24to8pal is a universal 8-bit palette for remapping 24-bit images. The
palette has been thoroughly optimized and tested with a wide variety of
demanding 24-bit images. The first eight colours are standard MagicWB
colors. The last four is available for custom usage.

Background: Since the AmigaOS color-reduction routines sucked so much I
created a preset 8-bit palette for remapping 24-bit images. The first
versions wasn't that great, but in any case they'd beat the system remapping
by far. Since then I have created somewhere around ten totally new versions
of such palettes -each and everyone better than the previus. The palette is
optimized to give a - for the eyes - concistant resolution in Velocity,
Saturation and Hue according to a datareduction model. Colors that the eyes
have difficulties separating - f.ex. colors in transitions between green and
yellow, white & yellow or black & blue - have been supressed in favour of -
for the eyes - more demanding transitions, f.ex. greyscales, black & yellow
or white & blue. In the same way the saturation range have been supressed in
favour of velocity. Many palettes came and went in order for me to balance
the palette properly.

The result is stunning concidering the use of a preset palette. After
remapping a 24-bit highresolution image to 8-bits with Floyd-Steinberg
dithering it can be difficult to see the difference from the original.
Especially if the original is a highly detailed image WITHOUT large
(seemingly) monocolored surfaces like a wall, a sky, etc. Detailed vistas
with litte or no sky will give a very good result. Blurry indoor images will
give the worst result.

Remapped example images can be found in a different archive. Hint:
'pic/misc/jet_24to8examples.lha'. I decided not to act like a complete jerk
and add 1MB with 24-bit and 8-bit before/after images to an archive that's
less than 5K in size. However, the archive contain a tiny IFF-image which
present the palette in multiple ways (I recommend using the zoom function of
PPaint or DPaint when viewing it).

24to8.iff   4770 Bytes      IFF-Image
24to8.pal    828 Bytes      IFF-CMAP


BTW, the time gap between the date of creation and the upload date have
absolutely nothing to do with me getting the next free Aminet CD in a row =)

Björn Östberg <JetRacer@hem.passagen.se> 99-11-26
