On Feb 15, 2016, at 1:16 AM, Schepers, Benjamin wrote:
> Hi,
>
> you still pointed to the right answer, strategies like overviews and tiling
> are IMHO not scale-dependent. They depend on the pixel-dimension of the image
> and you have - let’s say - a not so small one ;-)
>
> So converting to GeoTIFF with internal „Tiling“ could be the right strategy
> for you (http://www.gdal.org/frmt_gtiff.html; use “BigTIFF” if files are
> expected to be larger than 4GB) à hint: gdal_translate with “BIGTIFF=YES” and
> “TILED=YES” … and of course Overviews (gdaladdo; also possible with
> BigTIFF-option).
>
> Compression for original and overviews, could be lossless “LZW” or lossy
> „JPEG-YCBCR” for example, this would also substantially squeeze down the size
> an d depends on your needs…
>
> I have a lot of aerial images with up to 250.000*150.000px (GSD up to 6cm) in
> that manner and they are serving really, really fast via mapserver. Not every
> GIS-software is able to read those tiled and compressed BigTiffs directly
> (due to the lack of support for this file-format), but ArcGIS and QGIS do
> well (both use GDAL) and all others could still use the WMS served from
> mapserver!
Thanks for the advice. I was already using GeoTIFFs with internal
tiling, and compression.
The issue turned out to be a bad directive in the mapfile. Our
Mapscript application was misconfigured to set LOAD_WHOLE_IMAGE=yes in the
processing directives for small-area imagery. I don't recall why this was
done, but I changed it, and now the images load fine in tiled mode.
Thanks for your help.
--
Avi Blackmore
Head Programmer/System Administrator
Satshot Inc.
_______________________________________________
mapserver-users mailing list
mapserver-users@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/mapserver-users
