2011/9/28 Jorge Arévalo <jorge.arev...@deimos-space.com>: > I'm serving a NDVI coverage via Mapserver. So, one band, float32 > values, [-1.0, 1.0]. I want to display the NDVI in greyscale, and > generate a legend. I've tried 2 things: > > - Create two dummy classes, just for testing: > > CLASS > NAME "rojo" > EXPRESSION ([pixel] < 0.3) > STYLE > COLOR 255 0 0 > END > END > > CLASS > NAME "azul" > EXPRESSION ([pixel] >= 0.3) > STYLE > COLOR 0 0 255 > END > END > > So, my legend looks like this: http://dl.dropbox.com/u/6599273/leyenda.png > > And the image, obviously, is red and blue: > http://dl.dropbox.com/u/6599273/capturas/ndvi_en_gvsig.png > > But I'd like to see the image in greyscale... The I've tried the next thing > > - Pre-classify values with PROCESSING "SCALE=-1.0, 1.0". I don't know > what Mapserver internally does with this processing order, but I can > see the image in greyscale: > http://dl.dropbox.com/u/6599273/capturas/ndvi_gris_en_gvsig.png > > The problem is now I can't see any legend, because I've not created > any class. I'd like to see all the different levels of the grayscale > image in my legend. > > How could I do it? > > Many thanks in advance > > -- > Jorge Arévalo > Internet & Mobility Division, DEIMOS > jorge.arev...@deimos-space.com > http://es.linkedin.com/in/jorgearevalo80 > http://mobility.grupodeimos.com/ > http://gis4free.wordpress.com > http://geohash.org/ezjqgrgzz0g >
Ok, I've found a way, but I'm sure it isn't the shortest path. Basically, I've generated a legend using GRASS (r.colors to add grey color as color interpretation for band and d.legend to generate the legend). The legend is generated from the ndvi file. So, I guess I can create a HTML template as Mapserver legend, using the legend generated by grass (here: http://dl.dropbox.com/u/6599273/grass/grass_legend.png) On the other hand, I know how to generate a legend in Mapserver using CLASS objects in the mapfile, but I don't know how to generate that legend without the CLASS options in the mapfile. Am I taking the long way on this? Is there an easier way to generate a legend for a NDVI file in Mapserver? Many thanks in advance -- Jorge Arévalo Internet & Mobility Division, DEIMOS jorge.arev...@deimos-space.com http://es.linkedin.com/in/jorgearevalo80 http://mobility.grupodeimos.com/ http://gis4free.wordpress.com http://geohash.org/ezjqgrgzz0g _______________________________________________ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users