Forgot your password?
Document Actions
Proposal for an open source Python GIS processing API
Sure there's gdal and ogr bindings but we need something that works on a layer level.. like the arcgis geoprocessor but more object oriented and pythonic.
Overview
We want a simple, open source, object-oriented python API to build geospatial processing tools that access datasets on a layer/band level for vectors and rasters respectively. The following are example of what this might someday look like:All scripts start with
#!/bin/python
from whateverwecallthisthing import *
Example 1: Buffering all dirt roads in a roads coverage.
road_data = loadVectorDataset('/data/roads/')
roads = road_data.selectLayer(layername='aat')
dirt_roads = roads.selectByAttribute(query='type == "dirt"')
dirt_buffer = dirt_roads.buffer(distance=50, units=METERS)
dirt_buffer.save(format=SHP, path='/data/dirtbuffer.shp')Example 2: Reprojecting a raster DEM to the road's spatial reference (srs) and performing hillshade
dem_data = loadRasterDataset('/data/dem.img')
dem = dem_data.selectBand() #only 1 band so this will be sufficient
dem_proj = dem.reproject( srs = roads.getSrs() )
hillshade = dem_proj.hillshade( alt=45, angle=315 )
Example 3: Clip the hillshade to the roads extent and save
hillshade_clip = hillshade.clip( extent = roads.getExtent() )
hillshade_clip.save(format=TIFF, path='/data/hillshade.tif')
Very Rough API proposal
VectorDataset
Methods:
- selectLayer
RasterDataset
Methods:
- selectBand
RasterBand
Methods:
- save
- reproject
- hillshade
- aspect
- slope
- rasterAlgebra
- resample
- setSrs
- getSrs
- getExtent
- clip
VectorLayer
Methods:
- save
- selectByAttribute
- buffer
- reproject
- setSrs
- getSrs
- selectByLayer
- selectByBbox
- simplify
- join
- rasterize
- clip
- union
- intersect
- dissolve
- addField
- calculateField
- getExtent