[mapserver-dev] png optimization on output

[Paul Ramsey]

That would be nice. I have a client who wants XMP metadata embedded in
images, which is something that is more doable if one has more direct
access to the image libraries.

On Wed, Feb 17, 2010 at 11:07 AM, Lime, Steve D (DNR)
<Steve.Lime at state.mn.us> wrote:
> I believe so. Thomas was already using libpng directly under certain circumstances. I suppose we could make the decision to write directly through those libs and use GD for GIF only.
>
> Steve
>
> -----Original Message-----
> From: mapserver-dev-bounces at lists.osgeo.org [mailto:mapserver-dev-bounces at lists.osgeo.org] On Behalf Of Paul Ramsey
> Sent: Wednesday, February 17, 2010 9:54 AM
> To: thomas bonfort
> Cc: mapserver-dev
> Subject: Re: [mapserver-dev] png optimization on output
>
> I've been looking at the image writing code, and to an extent it seems
> well-hidden behind libgd. Do we have the option of writing directly
> through libpng/libjpeg?
>
> On Wed, Feb 17, 2010 at 1:23 AM, thomas bonfort
> <thomas.bonfort at gmail.com> wrote:
>> +1 for this functionality
>> libpng supports different levels of compression, so it might be nice
>> to expose those to the formatoption values instead of just TRUE/FALSE
>>
>> --
>> thomas
>>
>> On Tue, Feb 9, 2010 at 22:43, Stephen Woodbridge
>> <woodbri at swoodbridge.com> wrote:
>>> Thomas, Steve L, Assefa,
>>>
>>> Do we have an option to optimize png images for size on output?
>>> I'm using an output format like:
>>>
>>>  OUTPUTFORMAT
>>>    NAME "agg_qn"
>>>    DRIVER "AGG/PNG"
>>>    EXTENSION "png"
>>>    MIMETYPE "image/png"
>>>    IMAGEMODE RGB
>>>    FORMATOPTION "INTERLACE=false"
>>>    FORMATOPTION "QUANTIZE_NEW=ON"
>>>    FORMATOPTION "QUANTIZE_DITHER=OFF"
>>>    FORMATOPTION "QUANTIZE_COLORS=256"
>>>  END
>>>
>>> If Iuse pngcrush -reduce on the resulting file I get about 25%  reduction in
>>> size. it seems like it might be worthwhile to add code that does the same
>>> sort of thing maybe triggered by something like:
>>>
>>>    FORMATOPTION "REDUCE=true"
>>>
>>> I realize that this is costs additional time, but when using mapserver with
>>> something like Assefa's tilecache patch where you are actually drawing
>>> metatiles and chopping them into a cache, the trade off between time and
>>> size can be justified.
>>>
>>> I can write up a bug if people think this would be a good option.
>>>
>>> Thanks,
>>>  -Steve W
>>>
>>> _______________________________________________
>>> mapserver-dev mailing list
>>> mapserver-dev at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/mapserver-dev
>>>
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