Work done

I have updated the project trac page by gathering all the mails, post comments, related docs and new ideas together: http://trac.osgeo.org/gdal/wiki/WKTRasterDriver. So, I defined a new project plan, available for comments, of course.

I looked for more testing data, and I found ftp://ftp.remotesensing.org/geotiff/samples/. Useful.

Then, I continued working on the Dataset/RasterBand to achieve the Objective 1 (see project plan in trac). Still working…

Planned work for next week

Finish the basic version of the read-only driver: reading support for one-band raster, without overviews neither outdb support, from now. First objective.

Problems found

I loaded this tif file for testing: ftp://ftp.remotesensing.org/geotiff/samples/gdal_eg/cea.tif

gdal2wktraster.py -r cea.tif -t mountain_one_band -s 4267 -b 1 -k -I -O -V

And I got an assertion error:

File "/home/jorge/gsoc09/src/wktraster/scripts/gdal2wktraster.py", line 855, in wkblify_raster
 assert band_ov is not None

This error is in wkblify_raster function, when trying to get Overview 0 from RasterBand 1.The function “calculate_overviews” returns  0 overviews, but the loop is executed anyway (look at the commented part):

for nov in range(0, 1): # noverviews):

So, I decided to avoid the overview creation (not in my objective 1), load the raster without this option and investigate a bit more. My first checking was if  I was using an old version of gdal2wktraster script. Yes, I was. Time to svn update.

Once updated, I realized on some syntax changes. Basically:

  • The “-O” option now doesn’t exist. A new option “-l OVERVIEW_LEVEL” is used (How do you know the limit to OVERVIEW_LEVEL?)
  • New “-M” option, to execute VACUUM command against created tables. Good idea 🙂
  • The “-k option” now takes an additional param, the block size desired. Then, we don’t use the block size given by GDAL (why?)
  • As a consequence of previous change, the “-m blocksize” option has been deleted
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