[Discuss] ImageMagick

Bill Ricker bill.n1vux at gmail.com
Tue May 3 15:46:24 EDT 2022


On Tue, May 3, 2022 at 3:11 PM Rich Pieri <richard.pieri at gmail.com> wrote:

>
> Won't matter. PostScript, like PDF, is device independent. Any
> conversion from PS will be lossy if it is not configured correctly for
> the desired target. As Gregg noted, the OP needs to read the manual to
> find out how to do this for their specific sources and targets.
>

Agree.

Or even better, cut out the middle man and call invoke *GhostScript*
directly instead of indirectly through IM 'convert'.

I cheated and looked at ImageMagick pages.
Without GS, there's no PS/PDF support, as i anticipated (upthread).
(No point reinventing a rather large engine.)

The IM "*delegates.xml*" file has the default GS args for PS, PDF.
usr/share/doc/imagemagick-6-common/html/www/source/delegates.xml
on my system, and is it ugly.
( ^XML makes everything better.^  Or at least bigger.)
What it tells me is that 'convert' will only knows txt->ps,  ps->{eps,
pdf,print} and pdf->{eps,ps};
so how the ugly jpeg was produced is guesswork!
(Maybe there's a Verbose option to dump the spawned command's commandline?)

All or Most of which default GS arg-flags likely can be overridden on the
'convert' command but just go straight to GhostScript if Convert isn't
doing it for you.

(And to *Derek*'s suggestion, yes, the P in JPEG stands for Photograph. If
your image is not a Photograph or requires photographic level of shading,
use *PNG* instead. Anything computer-generated graphic short of a Blender
render is going to be degraded in JPEG, preserved in PNG. If your Blender
render is so rich it needs JPEG compression, congratulations. But Rich is
correct that just requesting )

-- 
Bill Ricker
bill.n1vux at gmail.com
https://www.linkedin.com/in/n1vux


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