Re: Titanic 3D images

[P3D John Ohrt <johrt@xxxxxxx>]

P3D Andrew Woods wrote:
> JPEG is lossy compression and can therefore lead to crosstalk in
> 3D interlaced images.  GIF format would probably be better (unless a very
> low JPEG compression ratio is used).

JPEG can be lossy, but doesn't have to be.  Just set the quality to
100%.  Unless you are satisfied with less than 256 colors, JPG is always
preferrable to .GIF.  This also holds for 256 levels in monochrome. 
With quality set to 100%, a 256 color Jpeg will be almost of identical
size to a 256 color gif of the same image.  No surprise here, they use
the same compression algolrithm, LZW.  LZW is proprietary and the
authour of even freeware, must get licensed by the patent holders!!!!

The best approach is to use .PNG, Portable Net Graphics format.  It uses
not proprietary algolrithms, virtually always outperforms lzw, and can
handle 48 bit colour in addition to the 24 and 8 of .JPG and the
256/64/16/4/2 of .GIF

Even the source code for compression and decompression is free never
mind the executables for several file formats.

.PNG is a Net standard which is fairly new.

Regards,
--
John Ohrt,  Regina, SK, Canada
johrt@xxxxxxx



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