bug#4367: 23.1; unable to view this png image

[Eli Zaretskii]

> From: "Xah Lee" <xah@xahlee.org>
> Date: Tue, 8 Sep 2009 20:32:37 -0700
> Cc: bug-gnu-emacs@gnu.org
> 
> Not sure what you mean updating libpng, since this is on Windows, i presume 
> any png lib is included in emacs...

No, they are not.  The only image library shipped with the precompiled
binary distribution is libXpm, because without it you don't have the
color icons on the toolbar buttons.  The other image libraries need to
be installed separately.

> or, humm... does this mean if i don't 
> have libpng program installed separated on Windows then emacs won't open 
> image files?

You won't be able to see PNG image files in Emacs, yes.  And libpng is
a DLL, not a program.

See the value of image-library-alist for the possible image libraries
Emacs supports for each image type.  You need to have at least one
installed for each type, to be able to visit images of that type