Re: [Libreoffice] Image Compression Patch

Hi Kendy.
Thanks again for checking into this. I've done more testing and I think the problem is with your 
image decoder (ImageMagick). The problem icons are encoded as RGB + Simple 1 'colour' transparency. 
It may be a bit unusual, but is supported by the PNG spec and works with LibO's png decoder fine. 
It seems one of the 'Fathers' of the png format- Glenn Randers-Pehrson - contributes to 
ImageMagick. If it hasn't been patched already, I'm sure they'd value a bug report.
I have checked the optimized icons several ways and as much as possible, but ultimately it is only 
through use we can catch any small oddities. I suggest we push the new icons upstream and await 
user feedback.
Many thanks,Andrew


> Subject: RE: [Libreoffice] Image Compression Patch
> From: kendy@suse.cz
> To: ace_dent@hotmail.com
> CC: pat@pathawks.com; libreoffice@lists.freedesktop.org
> Date: Sun, 24 Oct 2010 22:07:32 +0200
>
> Hi Andrew,
>
> On 2010-10-22 at 11:47 +0100, Andrew C. E. Dent wrote:
>
> > I've finished the process of lossless optimization for the
> > default_images pack.
> > The archive is available here:
> > http://people.bath.ac.uk/ea2aced/OOo/default_images.zip
>
> $ du -hs --apparent-size default_images.save/
> 6,3M  default_images.save/
> $ du -hs --apparent-size default_images
> 4,8M  default_images
>
> Nice! :-)  Thank you a lot!
>
> To check that everything is still the same, I created a script that
> checks 2 directories (original icons, and the optimized ones), converts
> the png's to xpm's and checks them for differences:
>
> http://cgit.freedesktop.org/libreoffice/build/tree/bin/check-artwork.sh
>
> Unfortunately, some of the icons differed - please see the attached
> list; I did not commit/push those, only the ones that were the same.
>
> Can you please check what was wrong?  I eg. see that
> svx/res/lightfromleft_22.png has originally a transparent background,
> but the optimized version has gray background.
>
> > I'd be most grateful if you could get this checked in to the
> > repository.
>
> Done :-) - with the exception of the attached list.
>
> Thank you a lot,
> Kendy