Skip to main content
Geographic Information Systems

Return to Question

added 187 characters in body
Source Link
YenTheFirst
YenTheFirst
  • 221
  • 2
  • 4

I'd like to analyze some raster data in Python using NumPy.

This data doesn't necessarily exist as a file on the filesystem, it could be the result of a query against PostGIS, or something transferred over the network.

Is it possible to get GDAL to read data from a buffer in memory, instead of requiring a filename?

I realize one solution could be to open up a named temp file, write the data to that, and pass it as a filename to GDAL, but that seems inefficient, and more likely to incur I/O bottlenecks. Additionally, in the case of PostGIS, it would be nice to read the native format directly, as opposed to converting it to some other file format and reading that.

Edit: to clear up a bit of confusion, just using the PostGIS driver directly won't work either, since the query could be for a raster analysis, rather than just data stored in the DB.

I'd like to analyze some raster data in Python using NumPy.

This data doesn't necessarily exist as a file on the filesystem, it could be the result of a query against PostGIS, or something transferred over the network.

Is it possible to get GDAL to read data from a buffer in memory, instead of requiring a filename?

I realize one solution could be to open up a named temp file, write the data to that, and pass it as a filename to GDAL, but that seems inefficient, and more likely to incur I/O bottlenecks. Additionally, in the case of PostGIS, it would be nice to read the native format directly, as opposed to converting it to some other file format and reading that.

I'd like to analyze some raster data in Python using NumPy.

This data doesn't necessarily exist as a file on the filesystem, it could be the result of a query against PostGIS, or something transferred over the network.

Is it possible to get GDAL to read data from a buffer in memory, instead of requiring a filename?

I realize one solution could be to open up a named temp file, write the data to that, and pass it as a filename to GDAL, but that seems inefficient, and more likely to incur I/O bottlenecks. Additionally, in the case of PostGIS, it would be nice to read the native format directly, as opposed to converting it to some other file format and reading that.

Edit: to clear up a bit of confusion, just using the PostGIS driver directly won't work either, since the query could be for a raster analysis, rather than just data stored in the DB.

Tweeted twitter.com/#!/StackGIS/status/395305200439025664
Source Link
YenTheFirst
YenTheFirst
  • 221
  • 2
  • 4

In Python, reading a GDAL raster from memory instead of a file

I'd like to analyze some raster data in Python using NumPy.

This data doesn't necessarily exist as a file on the filesystem, it could be the result of a query against PostGIS, or something transferred over the network.

Is it possible to get GDAL to read data from a buffer in memory, instead of requiring a filename?

I realize one solution could be to open up a named temp file, write the data to that, and pass it as a filename to GDAL, but that seems inefficient, and more likely to incur I/O bottlenecks. Additionally, in the case of PostGIS, it would be nice to read the native format directly, as opposed to converting it to some other file format and reading that.