Hello, I would like to discuss the loading of big images in QGIS: I have an aerial image with 56000 x 44000 pixel. I tried three different approaches. I wanted to just use one single file instead of tiles. I used gdal to prepare the images.
Here are my results: * ECW: - compresses fine - 500mb limit doesn't seem to apply if I use the -co "LARGE_OK=YES" - loads fine and fast with UMN - loads very, very long in QGIS: >4 minutes - once loaded zooming and panning is very quick * Erdas imagine (HFA) - spill files don't support compression, spill files have to be used if the filesize is bigger than 2GB - loads very fast in QGIS, less than a second - once loaded zooming and panning is slower compared with ecw * bigtiff: couldn't get this to work So, as a result I would, from a technical point of view, like to go with ecw, if the initial, very long loading time could be fixed in QGIS. So, here are my questions: - will I run into licensing problem with ecw?, esp. if my filesize is bigger than 500mb? - can the long loading times of the ecw files be fixed in qgis? - are there other better alternatives besides ecw/erdas imagine/bigtiff? Thank you for discussing this issue. Andreas -- Andreas Neumann Böschacherstrasse 6, CH-8624 Grüt/Gossau, Switzerland Email: [EMAIL PROTECTED], Web: * http://www.carto.net/ (Carto and SVG resources) * http://www.carto.net/neumann/ (personal page) * http://www.svgopen.org/ (SVG Open Conference) * http://www.geofoto.ch/ (Georeferenced Photos of Switzerland) _______________________________________________ Qgis-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-user
