artemp/trac2github — Issue #203: mapnik png256 support for opacity
Author: artemp
Created: 2011-10-09 20:20:28+00:00
State: open
Labels: Core_Library

In my application I am rendering several imagery layers which are divided into separate geotiffs. While using tilecache to seed the cache which is rendered by the openlayers javascript lib, the bounding box of each layer exceeds the raster data boundary at zoomed out levels and fills it black. With normal png the nodata is transparent so there is no conflict with other layers. If the same behavior could be replicated for png256 that would be great!

Simple example would just be to render a raster with a bounding box outside the raster data set using png256.