/schooner-tk

A collection of (hopefully) useful utilities for working with satellite images.

Primary LanguageC++MIT LicenseMIT

Schooner-tk

A collection of utilities for averaging, color correcting, and removing artifacts from satellite images. It complements GDAL and landsat util.

Installation

Schooner-tk requires OpenCV 3. To install OpenCV 3 on OSX, use Homebrew:

brew install opencv3

unless you want to fight with CFLAGS, LDLIBS, and PKG_CONFIG_PATH go ahead and link opencv3

brew link opencv3 --force

Be forewarned this will mess with anything that relies on opencv 2.

For linux distributions, use apt-get, pacman, yum, or whichever package manager is preferred.

Once OpenCV is installed, clone the repository.

git clone git@github.com:propublica/schooner-tk.git
cd schooner-tk

Use make to compile and install schooner.

make && make install

Once installed, each command can be called from your terminal with:

schooner-<utilityname>

Utilities

Schooner-blend

schooner-blend averages multiple datasets together on a per pixel basis in order to remove temporary artifacts such as small clouds, airplane contrails, and sensor malfunctions.

Each input dataset must be the same size and in the same projection.

Schooner-cloud

schooner-cloud creates a cloud and snow mask from a Landsat 8 Quality Assessment band.

Schooner-contrast

schooner-contrast attempts to automatically color correct a landsat image. It uses two algorithms, the first is CLAHE (Contrast Limited Adaptive Histogram Equalization) which attempts to color correct an image while improving the local contrast of the image.

The other is simple histogram stretching and clipping. The tool calculates a histogram by band, and stretches the raster values to the range 0 to 255. It also discards the top and bottom 0.05% of values.

Schooner-multibalance

schooner-multibalance automatically corrects each band of many datasets so that each dataset has a similar color profile. This is useful as a preprocessing step to schooner-blend.

Schooner-stich

schooner-stitch seamlessly stitches multiple images together.

Learn more

For more detail, please see the official documentation. For an example of a schooner-powered workflow, see jqtr.de/schooner/.