g3togif (was: web fax viewer...)

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Hi,

Luigi Rizzo wrote:
> I think the best results could be achieved by producing a gif file
> with about 100dpi on each direction and using antialiasing when
> scaling down (i.e the resulting file could have 3-4 grey levels).
> Any suggestion on which pipeline of pbm tools can do this (so as
> to test how big the gif file would be, and if it is worthwhile to
> write a standalone converter) ?

g3topbm | pnmscale -xscale 0.5 -yscale 0.5 | ppmtogif

(or something similar).

Unfortunately, this will take *ages* to complete, somethink like one 
minute per page on a P-166/64 Mb RAM.

> If this proves satisfactory, I suppose even the conversion can be done
> on the fly without too much concern; I do not belive a fax page is
> going to get hundreds of hit per day :) .

If we had a specialized conversion tool to do just this (shrink to 100 dpi
[which is fairly easy as the standard resolution is approx. 200x200 or 
200x100 dpi] and create a GIF from that) it should be reasonable fast, 
you're right.

What I would like to see, though, is a way to get different sizes of the
fax on the client side - some faxes really aren't readable at 100 dpi or
even less -- *without* transmitting the image twice.

Maybe use the image scaling functions built into many/most www browsers?

gert
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Gert Doering - Munich, Germany      gert@greenie.muc.de
fax: +49-89-3545980     gert.doering@physik.tu-muenchen.de
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