Julianne, You can use the Memory raster driver just like you would use any other format driver. Use the ReadRaster() function. Refer to http://www.gdal.org/gdal_tutorial.html
On Thu, May 5, 2011 at 7:59 PM, Juliannerc <[email protected]> wrote: > Thanks for the response. > > Are the code snippets below what you mean by the memory drivers? > > # > # Create a memory raster to rasterize into. > # > target_dr = gdal.GetDriverByName ('MEM') > > target_ds = target_dr.Create ('', > 1500, > 1500, > 3, > gdal.GDT_Byte) > ... > > # > # Create a memory layer to rasterize from. > # > rast_dr = ogr.GetDriverByName ('Memory') > > rast_ogr_ds = rast_dr.CreateDataSource ('wrk') > > That part of the example code works fine. The lines and polygons created > in > the ogr layer are rasterized as expected according to the transform > settings: > > # > # Run the algorithm. > # > err = gdal.RasterizeLayer (target_ds, > [2, 3, 1], > rast_mem_lyr, > burn_values = [240, 80, 200]) > > > At this point, I believe that the raster image(s) (per layer) are in the > memory because the write to the disk produces the expected image: > out_dr = gdal.GetDriverByName ('pnm') > > out_dr.CreateCopy ('./rasterize_1.ppm', > target_ds) > > My BIG question is whether or not there is a way to get at the memory > portion of the raster bands. The ideal way (in Python) would be to get a > numpy array as one does in the ReadAsArray option. However, I'm not sure > that there is a way, and if so, how to do it. > > I believe that the C interface allows one access to the data store using: > > OGR_Dr_CreateDataSource > > If all else fails, one can create the images, write them to disk (maybe > memory file?) and then read them back as needed. It seems unnecessary to > have to go through the compression/write step when the object is right > there. > > Further clarification would be very welcome. > > Julianne > > -- > View this message in context: > http://osgeo-org.1803224.n2.nabble.com/python-memory-driver-tp6332439p6334436.html > Sent from the GDAL - Dev mailing list archive at Nabble.com. > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev > -- Best regards, Chaitanya kumar CH. /tʃaɪθənjə/ /kʊmɑr/ +91-9494447584 17.2416N 80.1426E
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