Re: PNG export bug

[Alan Horkan <horkana maths tcd ie>]

On Tue, 13 Apr 2004, Justin Gombos wrote:

> Date: Tue, 13 Apr 2004 19:03:10 -0600
> From: Justin Gombos <mindfuq@zianet.com>
> Reply-To: dia-list@gnome.org
> To: dia-list@gnome.org
> Subject: Re: PNG export bug
>
> * Lars Clausen <lars@raeder.dk> [2004-04-13 16:37]:
> >
> > Interestingly, the .dia files for all but reston are also corrupt.
>
> Ah, I forgot about that.. my ISPs web ftp server has been corrupting
> most of what I upload lately.  I'll try to find another way to post
> them.  Locally, my dia files are fine, and only the three PNG files
> have that strange artifact.
>
> > It's interesting that the png files should be corrupt, as they're
> > created as a bitmap and then converted directly to png with libpng.
>
> Bitmap?  Why not vector?  I was assuming that since the dia-grams are
> vector, and PNG is vector capable, that bitmapping would be
> unnecessary.

PNG (Portable Network Graphic) is a raster (aka bitmap) graphics format.
PNG is not vector capable.  http://www.libpng.org/pub/png/
Perhaps you are thinking of SVG (Scalable Vector Graphics)?
http://www.w3.org/TR/SVG/

Sincerely

Alan Horkan
http://advogato.org/person/AlanHorkan/