refs #2551
Postgis raster_columns view is returning NULL values for raster
overviews with large scale factors. That issue in postgis is described
in http://trac.osgeo.org/postgis/ticket/3006
This causes two main problems:
- The first overview with scale = NULL is wrongly chosen for rendering
always
- The messed up scaling factor causes the render symbolizer to spent
an insane amount of CPU and memory to render a messed up tiles.
The patch in postgis is expected to be released with the new version, a
few months from now.
Conflicts:
plugins/input/pgraster/pgraster_datasource.cpp
image_data_32 -> image_data_rgba8
image_data_8 -> image_data_gray8
image_data_16 -> image_data_gray16
image_data_float32 -> image_data_gray32f
NOTE: currently image_data_gray16::pixel_type = std::int16_t (signed 16 bit int) to match GDAL
should we support unsigned types?
