This test case is intended to evaluate the speed of gdal_polygonize.py.

The basic test will simply run gdal_polygonize.py on the provided raster image and output a shapefile and report the processing time.

For comparison two additional methods can be used wherein the original raster is split into equal-sized chunks (8x8 is default) and then processed in serial or in parallel. Re-unioning the resulting chunks is not included in these processes.

The provided sample is a 4224x4224 tif that was produced first by running gdaldem hillshade and then reducing the colors to 2 using graphicsmagick, resulting in a binary black and white image (0 or 255).

Latest results (using GDAL 1.11.1)

• GDAL >= 1.11.1
• Python 2.7

Installing on OSX:

brew install gdal

Installing on Ubuntu:

apt-get install gdal-bin

wget https://mapbox-matt.s3.amazonaws.com/gdal-test/11_1444_804.tif
./test.sh [-m {single(default)|serial|parallel|all}]