This project contains some utilities to help and automate the procces of obtaining linear spectral unmixing of images stored in GRASS-GIS,. This utilities depends on the HyperspectralUnmixing program of the Orfeo Toolbox (https://www.orfeo-toolbox.org/CookBook/CookBooksu132.html#x165-10350004.10.4).
The project contains three utilities:
- clip_group_region: This utility clips, exports and stacks all the images of a GRASS image group (As otb_Hyperspectral_unmixing needs). The output raster name will be like:
originalname_subfixand will be stored in thewdfolder. Optionally it set the null values of the output images.
-end_rast_from_vect: This utility creates the endmembers raster image (end_raster) to use for unmixing. The endmembers will be stored as a multiband image, so that each band (b) holds the mean reflectance value of the (e) endmembers, resulting in a b x 1 x e raster. It takes the location of the pure pixels for each class from the point vector (endmember_location) and the column class_column.
- unmix: This utility performes spectral unmixing of the images stored in the 'gname' group, using the endmembers created with
end_rast_from_vect
The table below shows the arguments needed for each utility.
| Utility | Argument |
|---|---|
| clip_group_region | groupname,subfix,roi,nullval |
| end_rast_from_vect | vname,groupname |
| unmix | image,endmembers,out,utype |
-
GRASS imagery group (gname).
-
Region of interest (roi).
-
Vector containing the pure pixel (endmembers) location and "class id"
-
Unmixing method name (default = "ucls")
A multi band raster layer of abundance of endmembers for each "class id"
This program uses GRASS and Orfeo Toolbox. To install in Ubuntu/Mint/Debian open a terminal:
sudo add-apt-repository ppa:ubuntugis/ubuntugis-unstable
sudo apt-get update
sudo apt-get install grass otb otb-wrapping
To install the pipeline:
git clone https://github.com/leohardtke/spectral_unmixing.git
- Install the application
cd spectral_unmixing
pip install .
The test_db folder includes a sample GRASS GIS databes to test the pipeline
clip_group_region LE72270902000209EDC00_toar madryn madryn --overwrite
end_rast_from_vect endmembers class LE72270902000209EDC00_toar end madryn overwrite=True
unmix outputs/LE72270902000209EDC00_toar.tif outputs/LE72270902000209EDC00_toar_endmembers.tif outputs/unmixed_image.tif