[magick-users] Reading PNG with transparency broken

[Miro Dietiker]

Hi Anthony, thanks for response.

I received an out-list answer too. However that didn't solve the problem.

Anthony Thyssen schrieb:
> Miro Dietiker on  wrote...
> | I right switched from source files JPG to PNG source images in a database.
> | 
> | Aim was to introduce transparency.
> | 
> JPEG format can not save transparency!!!!
>   
Well i was not asking about JPG supporting transparency, but having a 
correct mapping into JPG.
I expected something transparent to be mapped into well defined thing.
However i realized now the -background white thing with flattening is 
needed.

But the thing is: when i do right that again - no matter how - it's the 
same result!
Still pattern in background - you could see the result here:
SRC:
http://www.frankonia-net.ch/imagemagick/M1800R2K8_YAY_2.png
OUT:
http://www.frankonia-net.ch/imagemagick/M1800R2K8_YAY_2.png.jpg
with
$ convert M1800R2K8_YAY_2.png -background white -flatten 
M1800R2K8_YAY_2.png.jpg

Experiments show that PNGs >4MB start having such pattern issues.
> | This is debian imagemagick:
> | Version: ImageMagick 6.0.6 02/11/07 Q16 http://www.imagemagick.org
> | Copyright: Copyright (C) 1999-2004 ImageMagick Studio LLC
> | 
> Also your IM is EXTREMELY old!
>   
Well this is debian sarge - OK conservative, old AND stable... but not 
necessarily broken ;-)

Now i have to admit:
On a debian etch 4.01 amd64 this works :-S with
Version: ImageMagick 6.2.4 02/10/07 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2005 ImageMagick Studio LLC

So there was a bug related, solved and not backported.
> Unfortunatally there is currently no way of generating new debian
> packages and no debian package experts know how to generate such
> packages.   If we can get the help of a debian expert we could
> probably setup the ability to generate of debian type packages.
>   
Looking into etchs imagemagick package, i see
Maintainer: Ryuichi Arafune <arafune at debian.org>
Depends: libbz2-1.0, libc6 (>= 2.3.5-1), libfreetype6 (>= 2.2), libice6 
(>= 1:1.0.0), libjasper-1.701-1 (>= 1.701.0), libjpeg62, liblcms1 (>= 
1.08-1), libmagick9, libpng12-0 (>= 1.2.13-4), libsm6, libtiff4, 
libx11-6, libxext6, libxml2 (>= 2.6.27), libxt6, zlib1g (>= 1:1.2.1)
Are those too ancient too? :-S

So primarily i'd contact him for any question about building some more 
up-to-date .dpkg
Will you ask him?

> The only suggestion I have is to install a personal version of IM for
> your system, outside the debian IM package.
>   
Yes, that would be the solution...
Now i changed my sources to TIF (LZW, transparency) from PNG and thing 
works - even without flattening and without setting background - out of 
the box....
--
Miro