I would like to use gdal_polygonize and gdalinfo in java. This site says: "Note that OSGeo4W includes a gdal-java package and a Java runtime making it fairly easily to build local Java applications using GDAL." But how?
You can see the source code for a gdalinfo java implementation here - https://svn.osgeo.org/gdal/trunk/gdal/swig/java/apps/gdalinfo.java
The polygonize function should be available in the java bindings, you may look at the source of gdal_polygonize.py to see how it's used - http://svn.osgeo.org/gdal/trunk/gdal/swig/python/scripts/gdal_polygonize.py