[MAPSERVER-USERS] help! agg palette quantize algorithmimperfection
Pål Kristensen
pal.kristensen at statkart.no
Tue Jun 10 03:18:37 EDT 2008
Hi!
Thanks for the quick answer! Is this feature considered to be includes as
"default" in the 5.2 release? If not I hope that the people maintaining the
MS4W would include this in that build. On Linux there is quite easy to build
MapServer, but on windows we still depends on the MS4W pre-build package.
Regards,
Pål Kristensen
tbonfort wrote:
>
> you still need --with-experimental-png
>
> thomas
>
> On Tue, Jun 10, 2008 at 9:01 AM, Pål Kristensen
> <pal.kristensen at statkart.no> wrote:
>>
>> Hi!
>>
>> Is the quantize mechanism for AGG now included as default, or do we still
>> need to build with the --with-experimental_png set?
>>
>> Regards,
>> Pål Kristensen
>>
>>
>> Steve Lime wrote:
>>>
>>> I've generated palettes by rendering a large 24-bit sample image and
>>> then
>>> reducing colors using
>>> tools like Photoshop, GIMP or ImageMagick. Then I just run gdalinfo
>>> output
>>> on the reduced color
>>> image through a perl script to extract the palette.
>>>
>>> #!/usr/bin/perl
>>>
>>> $doit = 0;
>>> while(<>) {
>>> if($_ =~ /Color Table/) {
>>> $doit = 1;
>>> next;
>>> }
>>>
>>> if($doit) {
>>> ($r,$g,$b,$a) = split /,/, substr($_,7);
>>> print "$r,$g,$b\n";
>>> }
>>> }
>>>
>>> Works just fine...
>>>
>>> Steve
>>>
>>>>>> On 6/6/2008 at 3:24 PM, in message <17700473.post at talk.nabble.com>,
>>>>>> BrainDrain
>>> <paulborodaev at gmail.com> wrote:
>>>
>>>> $? You're kidding)) Anyway, thanks for advise. Will try.
>>>> And what about agg rgba mode (bug, invalid color interpretation
>>>> (inverting?)
>>>> or something like that)? When
>>>> this problem will be fixed? I need it, because I want to use map
>>>> transparency (only rgba mode) to combine with google map layer in
>>>> openlayers
>>>> rich client app.
>>>>
>>>> Stephen Woodbridge wrote:
>>>>>
>>>>> Hey, that's what they pay you the BIG BUCKS for! :)
>>>>>
>>>>> Write a perl/bash/{your favorite} script to grab all the COLOR lines
>>>>> from you mapfile and reformat the r g b to r,g,b in you palette file.
>>>>>
>>>>> I have a few hundred symbols in my symbol library, but I only use
>>>>> about
>>>>> 10 of them regularly so I made sure the primary colors were also in
>>>>> the
>>>>> palette file. I make the script add them so I don't have to think
>>>>> about
>>>>> it.
>>>>>
>>>>> It sounds like a big deal, but it not that bad.
>>>>>
>>>>> YMMV,
>>>>> -Steve W
>>>>>
>>>>> BrainDrain wrote:
>>>>>> Thanks, i already read about preparing palette index file & I see 2
>>>>>> obstacles:
>>>>>> 1) I need to monitor my map file (big size) to keep relevant my
>>>>>> palette
>>>>>> file. It is inflexible to extract rgb colors used in pixmap symbols
>>>>>> (hundreds, updatable). Can I use html palette for ex. (or any other
>>>>>> 'universal' palette) - to make this process not so time-consuming?
>>>>>> 2) If I have strict palette, can I be sure that agg renderer will
>>>>>> always
>>>>>> use
>>>>>> the nearest(?) color from my palette?
>>>>>>
>>>>>> pagameba wrote:
>>>>>>> Use:
>>>>>>>
>>>>>>> OUTPUTFORMAT
>>>>>>> OUTPUTFORMAT
>>>>>>> NAME "AGG_Q"
>>>>>>> DRIVER "AGG/PNG"
>>>>>>> MIMETYPE "image/png; mode=8bit"
>>>>>>> IMAGEMODE RGB
>>>>>>> EXTENSION "png"
>>>>>>> FORMATOPTION "PALETTE_FORCE=TRUE"
>>>>>>> FORMATOPTION "PALETTE=/path/to/palette.txt"
>>>>>>> END
>>>>>>>
>>>>>>> where palette.txt is a text file with RGB tuples in the form:
>>>>>>>
>>>>>>> RRR,GGG,BBB
>>>>>>>
>>>>>>> For example:
>>>>>>>
>>>>>>> 0,0,0
>>>>>>> 255,255,255
>>>>>>> 127,127,127
>>>>>>>
>>>>>>> MapServer will use AGG 24 bit rendering but reduce the output file
>>>>>>> to
>>>>>>> 8 bit and reserve the colours in your palette.txt file. This will
>>>>>>> give you consistent colours for the ones you care about.
>>>>>>> Specifically, you should reserve all the colours that you actually
>>>>>>> reference in your map file plus any colours of pixmap symbols.
>>>>>>> Don't
>>>>>>> put in more colours than you actually need to because MapServer
>>>>>>> needs
>>>>>>> to use whatever space is left (255 less your colours) for
>>>>>>> antialiasing.
>>>>>>>
>>>>>>> Cheers
>>>>>>>
>>>>>>> Paul
>>>>>>>
>>>>>>> On 6-Jun-08, at 7:53 AM, BrainDrain wrote:
>>>>>>>
>>>>>>>> I use this output format in my map file:
>>>>>>>> OUTPUTFORMAT
>>>>>>>> NAME "AGG_Q"
>>>>>>>> DRIVER "AGG/PNG"
>>>>>>>> MIMETYPE "image/png; mode=8bit"
>>>>>>>> IMAGEMODE RGB
>>>>>>>> EXTENSION "png"
>>>>>>>> FORMATOPTION "QUANTIZE_FORCE=ON"
>>>>>>>> FORMATOPTION "QUANTIZE_DITHER=OFF"
>>>>>>>> FORMATOPTION "QUANTIZE_COLORS=256"
>>>>>>>> END
>>>>>>>> but every time map draw called (or map image requested fom cgi
>>>>>>>> mapserv.exe)
>>>>>>>> polygons has a little difference in fill color (I think this is
>>>>>>>> because
>>>>>>>> color palette recalculated slightly different each time). This is
>>>>>>>> unacceptable for me. How can i correct this? (maybe some
>>>>>>>> FORMATOPTION?)
>>>>>>>> --
>>>>>>>> View this message in context:
>>>>>>>>
>>>> http://www.nabble.com/help%21-agg-palette-quantize-algorithm-imperfection-tp1766773
>>>> 3p17667733.html
>>>>>>>> Sent from the Mapserver - User mailing list archive at Nabble.com.
>>>>>>>>
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>>>>>>>> mapserver-users at lists.osgeo.org
>>>>>>>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>>>>>>>
>>>>>>> __________________________________________
>>>>>>>
>>>>>>> Paul Spencer
>>>>>>> Chief Technology Officer
>>>>>>> DM Solutions Group Inc
>>>>>>> http://www.dmsolutions.ca/
>>>>>>> _______________________________________________
>>>>>>> mapserver-users mailing list
>>>>>>> mapserver-users at lists.osgeo.org
>>>>>>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
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>>
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