Re: flattening: two ways, two different results

On Thu, 31 Aug 2023, frechefuchs via Graphicsmagick-help wrote:
>
> Should I come across a show-stopper bug I will certainly fire-up a newer
> live system or perhaps even look into how to compile GM from source.
> I'm reading the GM changelog now and then.  All is well.

If you continue to persue using GM with so much energy, then building 
GraphicsMagick from source is reasonable.  The main requirement is to 
install the various "dev" libraries as well as the gcc or clang 
compilers.  Then it is easy. :-)

A fix for the PNG module aliases issue is already submitted.

> One more thing:  The PNG48, PNG64 and PNG00 format specifiers are not
> listed in the online list of supported formats at
> http://www.graphicsmagick.org/GraphicsMagick.html#desc .  I've only
> found them in the changelog.  (Much later than I originally needed them.
> No, I didn't know PNG supports 16 bits per channel back then.)

I was not very aware of these specifiers either.  They are not really 
"formats", but rather a way to request a particular permutation of the 
format.  These format specifiers used to be available and accessible 
but stopped being accessible after I made an implementation change.

Indeed, if a command was to access any form of PNG file and *then* 
request writing to "PNG64:file.png", then it would likely work in the 
version you have.

For example

    gm convert infile.png PNG64:outfile.png

would likely work.

Use this to get the full list of formats (which should be available):

    gm convert -list formats

Bob
-- 
Bob Friesenhahn
[email protected], http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
Public Key,     http://www.simplesystems.org/users/bfriesen/public-key.txt