Re: [Gimp-user] GIMP Message Image type 'png' is not supported

[YuGiOhJCJ Mailing-List <yugiohjcj-mailinglist laposte net>]

On Mon, 6 Jun 2016 02:22:04 -0400
Steve Kinney <admin pilobilus net> wrote:

> On 06/05/2016 08:28 PM, Bob Long wrote:
> > YuGiOhJCJ Mailing-List wrote on 06/06/16 07:13:
> >
> > > On Sun, 5 Jun 2016 23:11:43 +0200
> > > YuGiOhJCJ Mailing-List <yugiohjcj-mailinglist laposte net> wrote:
> > >
> > > > Hello,
> > > >
> > > > I have cross-compiled gimp-2.8.16 (from linux 32 bit to windows 32 bit).
> > > >
> > > > It runs well on Windows 8.1, but when I do "File > Save As... > Save", I get the following popup window:
> > > > "GIMP Message Image type 'png' is not supported"
> > > >
> > > > Any idea what could be the cause?
> >
> > You need to do "File > Export..." when "saving" as non-XCF format.
> >
> > > > Thank you.
> > > > Best regards.
> > >
> > > Here is a screenshot of this popup window:
> > > http://yugiohjcj.free.fr/gimp-save-xcf-error-png-not-supported.png
> >
> > My Web browser could not connect to that.
>
> wget wgot it.  It's a notification window with the title "GIMP Message,"
> saying:
>
> GIMP Message
> Image type 'png' not supported
>
> (OK button follows)
>
> I checked my local notification by "saving" a PNG file with GIMP 2.8.10
> on Mint.  I got a bigger notification window, with the title "Extension
> Mismatch," saying:
>
> You can use this dialog to save to the GIMP XCF format.  Use File >
> Export to export to other file formats.
>
> "Take me to the Export dialog" follows as an underlined hyperllink, and
> when clicked the notification window closes and replaces the Save dialog
> with the Export dialog.
>
> (OK button follows)
>
> If the notification dialog has not changed to the first one described
> above in GIMP 2.10.16, the problem sounds more like DLL Hell or
> something similar than export vs. save commands.  Is your compiled
> version linked to a PNG library it knows how to find and use?

Your "Extension Mismatch" notification window is not the same than mine.
Your notification window appears because you try to save an image on GIMP in the PNG format.
On GIMP, when you want to save an image you must use the XCF format.
If you want to save in PNG format, you need to export the image instead of saving it.
I am aware of that.

My notification window appears when I try to save an image on GIMP in the XCF format.
I know it is confusing because I save in XCF format but the notification window is about the PNG format.

I don't think that GIMP is unable to find a DLL because if that was the case, the program would not run at 
all.
When a DLL is missing, on Windows, I got a notification window telling me that I need a DLL.

So, I think that at compile time, GIMP or one of its dependencies requires the PNG library but can be 
compiled without it if not found.
So, I think the PNG support is disabled for a program or a library (maybe GIMP or one of its dependencies).
If you know a way to find what is the program/library that is not compiled with the PNG support please tell 
me because I have no idea.