Hi! To my knowledge a raster (or image) is always rectangular (you can have non square pixel though) . If the actual content is not rectangular, the boundary is filled with "some other data". You have a couple of choices on how to handle this.
1. Use the OFFSITE keyword in the layer object to "exclude" a certain pixel value, e.g OFFSITE 0 0 0 2. Use gdalwarp to mask no-data areas with a alpha channel I don't think it would make any sense to add non rectangular boundary polygon to the tileindex, because MapServer only uses the tileindex to determine which raster tiles to draw, no clipping is done (am I wrong??). It is the actual raster files that is processed, and they would still have the no-data pixels. Regards, Pål Kristensen victor valencia-2 wrote: > > Hi: > > I need to create a tileindex of several non-rectangular raster images. I > tried GdaltIndex, but produces rectangular polygons including the non-data > (Null) pixels. > These images i have are Landsat 7 saved as *.img, *.tiff, *.Sid. > These images are rhomboidal. Since the file is rectangular there is an > area with no valid pixels (non-data or Null). I need a boundary polygon > that exclude this pixels. > > I found an arcview 3x extension named Grid to Valid-pixel Polygon Catalog > w Stats, that creates a boundary polygons of the valid pixels, but works > just with Grid images. I could change the format of my images but this is > very very time consuming. > > Is there any script to create irregular bounding polygons > (non-rectangular) from the valid pixels for several images? > > Best regards > > Victor > > > > ______________________________________________ > Enviado desde Correo Yahoo! La bandeja de entrada más inteligente. > _______________________________________________ > mapserver-users mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/mapserver-users > > -- View this message in context: http://www.nabble.com/raster-tiling-of-non-rectangular-images-tp18334576p18338073.html Sent from the Mapserver - User mailing list archive at Nabble.com. _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users
