[Qgis-user] qgis and big raster catalogs

[Duarte Carreira]

Hi Qgisers!

One question: how to get a fast raster catalog in QGIS with a big number of rasters in it? (in this case 400 ecw)

I am having trouble getting this to work... I tried a vrt catalog and qgis just hangs when I load it.

Reducing the number of images makes it ok.

Is this a know limitation of gdal/qgis? Is there another approach to catalogs (not mosaics)?

What is the recommended approach to see a large number of images in QGIS when working at big scales (zoomed in)?

I thought of the following:

1-referenced shapefile catalog - like mapserver tileindex shapefiles

-          Qgis does not support this
2-vrt file

-          Qgis is too slow when there are many images in the catalog
3-referenced catalog in some other format? Sqllite?

-          Couldn't find an alternative
4-just load a directory full of rasters

-          I didn't even investigate this option since I figure this would be painfully slow every time you would load the directory...

One last detail: I'm using ecw images, but I'm betting this is not format related...

I appreciate your thoughts and knowledge on this:)

Regards,
Duarte
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