[mapserver-users] Re: AGG OUTPUTFORMAT Question

[thomas bonfort]

just a side note on the subject: seeding your tiles probably involves
using tilecache's metatiles. quantizing a 5x5 tile in mapserver will
very probably give poorer visual results than quantizing each
individual tile. For this reason I tend to seed in 24bit mode, and
postprocess the split up tiles with pngnq:

for file in `find tilecache/mylayer -name "*.png"`;
do
 echo $file;
 pngnq -e .png.tmp -n 256 $file;
 mv $file.tmp $file;
done

On Wed, Dec 17, 2008 at 20:56, thomas bonfort <thomas.bonfort at gmail.com> wrote:
> Steve,
>  you have the undocumented FORMATOPTION QUANTIZE_NEW=yes that uses the
> median cut quantization algorithm which is slower but much better than
> the GD one. Still no guarantee your tiles will have exactly the same
> colors, although in practice this seems to be the case.
>
> keep me in touch with your findings, so this can be documented if the
> results are ok.
>
> cheers,
> thomas
>
> On Wed, Dec 17, 2008 at 20:38, Stephen Woodbridge
> <woodbri at swoodbridge.com> wrote:
>> Hi Thomas, et al,
>>
>> I need to generate tiles using AGG output and need them to be 8 bit png
>> images.
>>
>> http://mapserver.gis.umn.edu/docs/howto/agg-rendering-specifics
>>
>> Does not make it clear if any of the formats shown are 8 bit png images and
>> it does not note the use of:
>>
>>    FORMATOPTION "PALETTE_FORCE=TRUE"
>>    FORMATOPTION "PALETTE=/u/data/maps/palette-agg.txt"
>>
>> What is the proper way to set up OUTPUTFORMAT to use AGG to get the best
>> quality 8 bit output. I think I need to use the PALETTE* options to control
>> color shifts in adjacent tiles.
>>
>> I would be happy to add a comment to the above link with this additional
>> info.
>>
>> Best regards,
>>  -Steve W
>>
>