Building Extractor Documentation


This software extracts building locations from USGS DRG (Digital Raster Graph) files.   It may also work with similar files produced by other organizations, such as scanned international topo quads.  The input file is expected to be a TIF, and the output is a VTST (Structures File).

Required Software

The Image Processing Library (IPL) must be installed for you to compile or run this program. This can be obtained from the VTP CD.  Unfortunately it is no longer available directly from its creator.

You may also need to copy the IPL DLLs from the directory in which they were installed (usually C:/Program Files/Intel/plsuite/bin) to a directory on your path (for example, C:/winnt)

Required RAM

If you are going to process a full-size DRG, be aware that you should have at least 128 MB of RAM on your machine - more is better.


Once an image is loaded, user can do the following:


Extract Buildings -- This function is the meat of the application, and is composed of the following parts:

Clear Selected Buildings -- This function clears all building marks from the image. Useful if the user wants to try a different kernel size or threshold setting on an image.

TestIPL -- This function is of no use for building recognition. It was used to test certain aspects of the Intel Image Processing Library during development.

Use of VTST Files

In order to use the VTST files you have generated, copy them to the VTP Enviro data directory Enviro/Data/BuildingData.  The next time you run Enviro, they will appear on the "Structures Filename" drop-down control of the Terrain Parameters dialog.