Today getting a good raster processing environment is not so difficult. The computers are cheaper, storage components are bigger and prices are lower than any time before. Internet is full of tutorials and tips for people who want to start building their own remote sensing lab. This post will reintroduce three most common open-source raster and vector processing libraries which anyone can use – GDAL, RSGISLib Python library and Orfeo Toolbox.

In this article I have used a 64bit Lubuntu environment in Virtualbox with 2GB RAM and 10GB SATA space dedicated.

Installing GDAL

One of the amazing thing about Ubuntu is that has its own application channel or package archive (PPA) dedicated to spatial analysis and application. It’s called UbuntuGIS. Adopting the original DebianGIS, the stable platform of UbuntuGIS has lot of features providing all the stable releases while the unstable version has all the latest packages and libraries.

Geospatial Data Abstraction Library (GDAL) is a set of open-source command-line spatial data translation and analysis toolset for many data format. The easiest way to install GDAL with native Python of Lubuntu, use this line

And to get GDAL’s command line utility use this.

Windows users can use a very useful little installer called OSGEO4W which can be used to install GDAL and other important utilities. Here is an amazing tutorial to install GDAL with Python binding in windows.

Making use of GDAL

To get a few of the basic information let’s use the gdalinfo utility.

Quite self-explanatory. GDAL can also access Landsat .tar.gz archive.

GDAL scripting environment can be accessed inside python with os.system. Using GDALWARP you can batch reproject many file at once.

Getting RSGISLib and GDAL with Miniconda

If you want to make your setup sandboxed and isolated from the default Lubuntu Python environment you might want to use Miniconda. Miniconda is a Python distribution platform and also a lighter version of a more robust platform called Anaconda. It’s completely free and can be used with both Python 2.x and 3.x in both x86 and x64 OS. RSGISLib is a python library for satellite image processing and analysis. Unfortunately RSGISLIB has some complication with Anaconda, so I used Miniconda. Miniconda comes with the mighty CONDA command tool so you can always install and update libraries you need. To install RSGISLib simply hit this line in the terminal

This should download and install all the necessary libraries to your system. But Ubuntu users may face some dependency issue for DGAL. For Ubuntu users, use these command before conda command

RSGISLib is only available for Linux and OSX users, windows users will have to compile from source.

Making use of RSGISLib

Not only for preprocessing, RSGISLib can be used to do quite high level of raster analysis, image segmentation, LiDAR processing, vector processing and other useful stuff.Here is a small example to mosaic a set of KEA images in a folder.

To give projection to an image using another one use this.

The segutils tool can be used for OBIA and image classification

These segments can be used for further analysis with attribution and feature extraction.

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