hi bug http://trac.osgeo.org/mapserver/ticket/2436 addresses this issue and should be included in 5.2
regards, thomas On Dec 19, 2007 8:27 AM, Pål Kristensen <[EMAIL PROTECTED]> wrote: > Hi! > > The AGG renderer it self can not produce 8bit output, but as stated in the > RFC GD is actually used to handle the images. The quantize method for > reducing color depth from 24bits to 8bits works quite well with the AGG > renderer, but not if the WMS parameter TRANSPARENT is set to true. I guess > this has something to do with the fact that GD interprets the alpha channel > > backwards, hence the resulting image is in some way "broken". But for some > reason, I don't know why, this is not the case when 24bit images is > delivered the transparency works perfectly well. > > Regards > Pål Kristensen > > > > Travis Kirstine wrote: > > > > Sorry Pal I have no advice just a comment. We were considering > > upgrading to ms 5.0 with agg but never did do to the statment on the > > mapserver site "The AGG driver only supports RGB output at this time." > > on the Support for Anti-Grain Geometry (AGG) Rendering Engine > > documents. > > > > http://mapserver.gis.umn.edu/development/rfc/ms-rfc-32 > > > > I guess this in not correct? > > > > Travis > > > > > > > > > > > > > > > > > > > > > > > > > > On 17/12/2007, Pål Kristensen <[EMAIL PROTECTED]> wrote: > >> Hi! > >> > >> I'm trying to use the AGG renderer and reduce the resulting 24bits image > >> to > >> 8bits by using the quantize method. This works quite well when the WMS > >> parameter TRANSPARENT=false, but when set to true the BGCOLOR parameter > >> seems to be ignored and the quality of the rendered vectors clearly > >> degrades. > >> > >> When requesting 24bit images the TRANSPARENT parameter works correctly. > >> See > >> the examples below: > >> > >> 24bit png, transparent true -> OK: > >> http://159.162.103.7/cgi-bin/NorgeTopo?VERSION=1.1.1&SERVICE=WMS&REQUEST=GetMap&SRS=EPSG:32633&BBOX=62423.20,6794915.15,66383.94,6797147.88&LAYERS=Hoydekurver&STYLES=&WIDTH=926&HEIGHT=522&FORMAT=image/png;%20mode=24bit&BGCOLOR=0xffffff&TRANSPARENT=true > >> > >> 24bit png, transparent false -> OK: > >> http://159.162.103.7/cgi-bin/NorgeTopo?VERSION=1.1.1&SERVICE=WMS&REQUEST=GetMap&SRS=EPSG:32633&BBOX=62423.20,6794915.15,66383.94,6797147.88&LAYERS=Hoydekurver&STYLES=&WIDTH=926&HEIGHT=522&FORMAT=image/png;%20mode=24bit&BGCOLOR=0xffffff&TRANSPARENT=false > >> > >> 8bit png, transparent false -> OK: > >> http://159.162.103.7/cgi-bin/NorgeTopo?VERSION=1.1.1&SERVICE=WMS&REQUEST=GetMap&SRS=EPSG:32633&BBOX=62423.20,6794915.15,66383.94,6797147.88&LAYERS=Hoydekurver&STYLES=&WIDTH=926&HEIGHT=522&FORMAT=image/png&BGCOLOR=0xffffff&TRANSPARENT=false > >> > >> 8bit png, transparent true -> NOT OK: > >> http://159.162.103.7/cgi-bin/NorgeTopo?VERSION=1.1.1&SERVICE=WMS&REQUEST=GetMap&SRS=EPSG:32633&BBOX=62423.20,6794915.15,66383.94,6797147.88&LAYERS=Hoydekurver&STYLES=&WIDTH=926&HEIGHT=522&FORMAT=image/png&BGCOLOR=0xffffff&TRANSPARENT=true > >> > >> This is the output formats from the mapfile: > >> ... > >> OUTPUTFORMAT > >> NAME "png8bit" > >> DRIVER "AGG/PNG" > >> MIMETYPE "image/png" > >> EXTENSION "png" > >> FORMATOPTION "QUANTIZE_FORCE=ON" > >> FORMATOPTION "QUANTIZE_COLORS=256" > >> FORMATOPTION INTERLACE=OFF > >> END > >> > >> OUTPUTFORMAT > >> NAME "png24bit" > >> DRIVER "AGG/PNG" > >> MIMETYPE "image/png; mode=24bit" > >> EXTENSION "png" > >> IMAGEMODE "RGB" > >> FORMATOPTION INTERLACE=OFF > >> END > >> > >> OUTPUTFORMAT > >> NAME "jpeg24" > >> DRIVER "AGG/JPEG" > >> MIMETYPE "image/jpeg" > >> EXTENSION "jpg" > >> FORMATOPTION "QUALITY=60" > >> END > >> ... > >> > >> Regards, > >> Pål Kristensen > >> -- > >> View this message in context: > >> http://www.nabble.com/AGG-renderer-in-conjunction-with-WMS-TRANSPARENT%3Dtrue-parameter-tp14370293p14370293.html > >> Sent from the Mapserver - User mailing list archive at Nabble.com. > >> > > > > > > -- > > Travis K. > > > > Toronto, Canada > > ------------------------------------------------------------ > > "She knows there's no success like failure > > And that failure's no success at all." > > -Bob Dylan- > > ------------------------------------------------------------ > > > > > > -- > View this message in context: > http://www.nabble.com/AGG-renderer-in-conjunction-with-WMS-TRANSPARENT%3Dtrue-parameter-tp14370293p14412307.html > Sent from the Mapserver - User mailing list archive at Nabble.com. >