Open segoerke opened 10 years ago
Seems to be a be a good idea and a usefull feature.
Beeing able to transform Tiles would be a benefit, but could also be a performance problem if the transforatiom will require to fetch some or all 8 neighbour tiles.
We at lat/lon worked on this feature for a few weeks. Our approach was not to render every single tile, but create the image as it is created now and then transform the complete image into the new crs. The benefits are, that every tile needs to be fetched only once, the transformation needs to be done only once and there are no breaks on the transformed tiles' boundarys.
We do recommend to use the GdalLayer or GdalTileStore (see https://download.deegree.org/documentation/3.4.11/html/#anchor-configuration-gdal-layer) for distributing raster images with different projections other than the datasource provides.
Instead of using a file based datasource raster images can be stored in a database. Currently deegree supports this only for Oracle DBMS. A feature request for PostGIS Raster is documented in #785.
For pure image display pruposes through a WMS service, it is needed, that deegree tile stores have support for coordinate transformation. In the current situation you'll have to serve your datasource in every projection to be supported. Tests have shown that the old coverage api is able to provide raster images through WMS with a good performance with the pyramid file configuration for GeoTiff. As deegree's tiling api is much cleaner than the coverage api, it is a good idea to enable transformation support for tile stores to avoid having duplicated datasources etc.