Hi Jaume, You might be able to combine two gdal layers without blending by using a GDAL VRT file:
http://www.gdal.org/gdal_vrttut.html The idea would be to point Mapnik then at that single VRT. Beyond that seeing a visual example of the output you are looking for might be a good next step. Dane On Nov 10, 2010, at 6:06 AM, Jaume Figueras i Jové wrote: > Hi all, > > I'm beginning to use mapnik and I'm trying to draw a map using mapnik with > different logical layers: > > Base: vector layer (A) with land information > Layer (B) with imaginery in GeoTIFF > Layer (C) with other images in GeoTIFF > Top: vector layer (D) with road information > > I'm using blending in the style with layers B & C, so > > A -> grain_merge B -> hard_light C > > <Style name="rasterB"> > <Rule> > <RasterSymbolizer> > <CssParameter name="scaling">bilinear</CssParameter> > <CssParameter name="mode">grain_merge</CssParameter> > </RasterSymbolizer> > </Rule> > </Style> > > <Style name="rasterC"> > <Rule> > <RasterSymbolizer> > <CssParameter name="scaling">bilinear</CssParameter> > <CssParameter name="mode">hard_light</CssParameter> > </RasterSymbolizer> > </Rule> > </Style> > > Layer B is composed of different images so I define different layers, one for > each image as: > > <Layer name="B_img01"> > <StyleName>rasterB</StyleName> > <Datasource> > <Parameter name="type">gdal</Parameter> > <Parameter name="file">img1.tiff</Parameter> > </Datasource> > </Layer> > > <Layer name="B_img02"> > <StyleName>rasterB</StyleName> > <Datasource> > <Parameter name="type">gdal</Parameter> > <Parameter name="file">img2.tiff</Parameter> > </Datasource> > </Layer> > > The problem is that, as defined in the style, when img1 and img2 overlap they > are blended, but what i would like to do is first combine the img1 and img2 > with no blending and then blend the result. Is there any way to do this in > mapnik or I need to GIMP the overlapping images first? > > TIA. > -- > Jaume Figueras i Jové > Ubuntu User #14347 - Linux User #504317 > > Universitat Politècnica de Catalunya > Departament d'ESAII > Edifici TR11 > Rambla Sant Nebridi, 10 > 08222 TERRASSA > Telf: +34937398621 (intern UPC: 98621) > Mòbil: +34650756456 (intern UPC: 44785) > Fax: +34937398628 (intern UPC: 98628) > > Centre de Simulació i Optimització de Processos Logístics (LogiSim) > http://logisim.fib.upc.es > > Enginyeria de Sistemes, Automàtica i Informàtica Industrial (ESAII) > http://webesaii.upc.es > > Universitat Politècnica de Cataluyna > http://www.upc.edu > > _______________________________________________ > Mapnik-users mailing list > [email protected] > https://lists.berlios.de/mailman/listinfo/mapnik-users _______________________________________________ Mapnik-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/mapnik-users
