[Qgis-developer] rasterdataprovider roadmap?

Peter Ersts ersts at amnh.org
Mon Jan 5 10:54:08 EST 2009

G. Allegri wrote:
> In the past days I've begun "studying" qgis source code, to understand
> the raster subsystem. 
Howdy Giovanni! Good to see others looking under the hood. We are in 
need of more people to work on the raster code, so if you are interested...

> I've seen that it is mostly included in the
> "core/raster/" folder code, dedicated to the reading (and a certain
> manipulation) of gdal supported formats. In fact the
> "rasterdataprovider", at this moment, is a wrap on gdal methods
the Raster capabilities are basically totally dependent on GDAL. GDAL 
will always be the default, but I think it would be good to provide the 
ability to have other providers as well.  The goal for v1.0.0 was to get 
the current approach stable and as usable as possible.

Currently the QgsRasterLayer class is a beast and really needs to be 
refactored into about 3 or 4+ classes. The idea is to make the raster 
providers much more like the vector providers. Tim provided a link to 
some of the initial brain storming.

> the only exported ability is "Identify". 
The raster system is read only. I would like to see numerous other 
accessors to pixel data; access by pixel coordinate, real world 
coordinate, request NxN blocks of pixels etc.

Another part of the raster system that is need is some basic raster 
manipulations; recoding values, calculators etc. Some of these exists as 
plugins but should be part of the core application and the API should be 
able to provide better access so.


Peter J. Ersts, Project Specialist
American Museum of Natural History
Center for Biodiversity and Conservation
Central Park West at 79th Street
New York, New York 10024
Tel: Home Office (518)-632-4745 or NYC Office (212)-496-3488
Web: http://biodiversityinformatics.amnh.org
Web: http://cbc.amnh.org

Quantum GIS Raster Development Team. Visit http://www.qgis.org
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