[Mapserver-users] Transparency values - confusion

[Dylan Keon]

I'm pretty sure you're not getting 24-bit output with this, since you're 
using IMAGEMODE PC256.  This may be why you're not noticing a change in 
transparency.  Regular 8-bit output defaults to PC256.  Try IMAGEMODE 
RGB in your png24 entry and see if it makes a difference.

See http://mapserver.gis.umn.edu/cgi-bin/wiki.pl?OutputFormat for more 
info on IMAGEMODE.

--Dylan



randy james wrote:
> Hi
> 
> Mine is like this:
> 
> <!-- MapServer version 3.7 (development) OUTPUT=PNG
> OUTPUT=JPEG OUTPUT=WBMP SUPPORTS=PROJ SUPPORTS=TTF
> SUPPORTS=WMS_SERVER SUPPORTS=GD2_RGB INPUT=EPPL7
> INPUT=JPEG INPUT=POSTGIS INPUT=GDAL INPUT=SHAPEFILE
> -->
> 
> IMAGETYPE png24
> 
>  OUTPUTFORMAT
>     NAME png24
>    MIMETYPE "image/png"
>     DRIVER "GD/png"
>    IMAGEMODE PC256
>   END
> 
> layer
>     data "92i_mod"
>     name 'aoa'
>     status off
>     type polygon
>     transparency 30
>     # 1 class #none
>     class
>     name 'aoa_mod'
>       color 255 255 0
>     end
>   end
> 
> Cheers
> Randy
> 
> --- Dylan Keon <keon at nacse.org> wrote:
> 
>> > --- Dylan Keon <keon at nacse.org> wrote:
>> >> I've noticed the same thing in 3.7.  When I
>>switch
>> >> between 8-bit and
>> >> 24-bit output I have to invert my transparency
>> >> values (i.e., change 25
>> >> to 75 and vice-versa) to get the same effect.
>> >
>>randy james wrote:
>>
>>>I have been testing outputformat and switching
>>
>>between
>>
>>>PNG and PNG24 and never had to change anything.
>>
>>Have
>>
>>>you been using outputformat?
>>
>>Yep, I'm using OUTPUTFORMAT for both.  I can toggle
>>between the 
>>imagetypes and see the transparency change on a
>>polygon layer when I 
>>refresh the map.
>>
>>#IMAGETYPE png8
>>IMAGETYPE png24
>>
>>OUTPUTFORMAT
>>   NAME png8
>>   DRIVER "GD/PNG"
>>   MIMETYPE "image/png"
>>   IMAGEMODE PC256
>>   FORMATOPTION "INTERLACE=ON"
>>END
>>OUTPUTFORMAT
>>   NAME png24
>>   DRIVER "GD/PNG"
>>   MIMETYPE "image/png"
>>   IMAGEMODE RGB
>>   FORMATOPTION "INTERLACE=ON"
>>END
>>
>>LAYER
>>   NAME boundary
>>   STATUS ON
>>   TYPE POLYGON
>>   DATA sevbnd83
>>   TRANSPARENCY 35
>>   CLASS
>>     NAME "Boundary"
>>     OUTLINECOLOR 110 110 110
>>     COLOR 243 248 245
>>   END
>>END
>>