Frank,<br> I have increased the cache as you suggested using GDALSetCacheMax and it produced a performance gain. Thanks.<br><br>I think I can improve more acting on the virtual datataset that I use to adapt the image to the paper size.<br>
I have to look into the tms driver in order to understand how it download the tiles to compose the final image.<br><br>Stefano<br><br><div class="gmail_quote">On Fri, Jun 11, 2010 at 6:17 PM, Frank Warmerdam <span dir="ltr"><<a href="mailto:warmerdam@pobox.com">warmerdam@pobox.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="im">Stefano Moratto wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Frank,<br>
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.<br>
It is explained very well in<br>
<a href="http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection" target="_blank">http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection</a>.<br>
<br>
I use interpolation (via a virtual dataset) because my window size and the paper size are not a multiple of 256 x 256.<br>
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.<br>
<br>
So I think the key factor is the resizing ( I use "bilinear" interpolation) and the size of the bitmap that may cause paging.<br>
</blockquote></div>
...<div class="im"><br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Can you suggest some other parameters?<br>
</blockquote>
<br></div>
Stefano,<br>
<br>
Sorry, I wasn't able to learn much more skimming the code and<br>
referenced web page. Have you tried the cache size setting<br>
I suggested?<div><div></div><div class="h5"><br>
<br>
Best regards,<br>
---------------------------------------+--------------------------------------<br>
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<br>
</div></div></blockquote></div><br><br clear="all"><br>-- <br>Dr.Eng. Stefano Moratto<br><a href="mailto:stefano.moratto@gmail.com">stefano.moratto@gmail.com</a><br><a href="mailto:stefano.moratto@csiat.it">stefano.moratto@csiat.it</a><br>
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