CartoDB VisualRaster For Deforestation

2012 Foss4G NA Presentation

Transcript

2. Intro to cartodb
3. Cartodb + PostGIS2.0
4. Raster
5. show drag drop
6. SELECT (ST_SummaryStats(rast)).* FROM hapctnpp_geotiff
9. UPDATE hapctnpp_geotiff SET rast = ST_MapAlgebraExpr(rast, '8BUI', 'CASE WHEN [rast] = 0 THEN 10 WHEN [rast] = 255 THEN 11 ELSE floor([rast]/32)::int END') ; Down-sampling
10. Raster to polygons select st_multi( st_makevalid( (geomval).geom) ) as the_geom, (geomval).val as value from (select ST_DumpAsPolygons(rast) as geomval from hapctnpp_geotiff) f
12. https://viz2.cartodb.com/tables/ pop_density_bins/embed_map?sql=select %20the_geom_webmercator%2C %20population%20from %20pop_density_bins%20
15. Spatial query WITH foo AS ( SELECT ST_AsRaster(triangle.the_geom, rast ) AS rast FROM triangle, hapctnpp_geotiff WHERE ST_Intersects(triangle.the_geom,rast) LIMIT 1) SELECT (ST_SummaryStats(ST_Union(ST_MapAlgebraExpr(m. rast, f.rast, '[rast1.val]', '16BUI')))).* as rast FROM hapctnpp_geotiff m JOIN foo f ON ST_Intersects(m.rast, f.rast);
17. DEMO
18. Thoughts
19. tiling of tiffs unknown
20. performance improvements still needed
21. Maps API support still needed