Frank, I have increased the cache as you suggested using GDALSetCacheMax and it produced a performance gain. Thanks.
I think I can improve more acting on the virtual datataset that I use to adapt the image to the paper size. I have to look into the tms driver in order to understand how it download the tiles to compose the final image. Stefano On Fri, Jun 11, 2010 at 6:17 PM, Frank Warmerdam <warmer...@pobox.com>wrote: > Stefano Moratto wrote: > >> Frank, >> The source images are a sequence of tiles from openstreetmaps. >> Every tiles has a fixed size (256 x 256) and the area they covers depends >> from the zoom level. >> It is explained very well in >> http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection. >> >> I use interpolation (via a virtual dataset) because my window size and >> the paper size are not a multiple of 256 x 256. >> I use reprojection because I've to mix this raster datasource with a >> vector datasource that has a different projection. Reprojecting my vector >> data to openstreet projection do not affect the performance. >> >> So I think the key factor is the resizing ( I use "bilinear" >> interpolation) and the size of the bitmap that may cause paging. >> > ... > > Can you suggest some other parameters? >> > > Stefano, > > Sorry, I wasn't able to learn much more skimming the code and > referenced web page. Have you tried the cache size setting > I suggested? > > > Best regards, > > ---------------------------------------+-------------------------------------- > I set the clouds in motion - turn up | Frank Warmerdam, > warmer...@pobox.com > light and sound - activate the windows | > http://pobox.com/~warmerdam<http://pobox.com/%7Ewarmerdam> > and watch the world go round - Rush | Geospatial Programmer for Rent > > -- Dr.Eng. Stefano Moratto stefano.mora...@gmail.com stefano.mora...@csiat.it http://www.csiat.it - Traffic Optimization Software
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