Water cycle, land use, and ecosystem studies requires the evaluation of satellite imagery from a long observation period. Images need be clipped to the area of interest, filtered, scaled, converted to desired formats and stored on defined folder structure. Current GIS desktop applications are fully capable of this spatial management and analysis when the amount of raster images is limited; however when we deal with high amount of images the spatial processing on a graphical user interface (GUI) can be slow and most commonly impractical. The use of programming / processing languages like Python and advanced spatial libraries as GDAL (gdal.org) helps on the spatial data transformation on a more abstract and effective way. This tutorial shows the complete procedure to clip the complete set of bands from a Landsat 8 image and store them with a suffix on every band file on another folder.

The tutorial is done on a interactive Python programming platform called Jupyter Notebook. The input files: raster bands and area of interest (AOI) shapefile need to be on the same system of reference (SRC), otherwise the GDAL library cannot locate the spatial data on the right position. The tutorial shows the procedure for the whole set of band form a Landsat 8 image, an example for a single band is provided on the scripts of the input data. Finally the tutorial shows the complete and clipped raster on a GIS desktop software as QGIS.

For beginners GIS users with few programming experience, it is advice to complete the tutorial with the sample data provided on the input data part of this tutorial. Once the user has more experience with the software, the user can modify the code for custom raster image processing.

Tutorial

For the installation of GDAL and other spatial libraries please check this tutorial: https://www.youtube.com/watch?v=4ybddFC80fU

Python code

This is the python code for multiple Landsat 8 raster band clipping:

Import requires libraries

This tutorial only requires the GDAL library and core Python libraries as the Operating System (OS) library.

from osgeo import gdal
import os

Setting up the input and output files

We set the routes for the input and outfiles, then we create a list comprehension that reads all files on a folder and filter only the TIF files.

#Input and output paths
#inputPath = '../Images/'
inputPath = '../Images_c1/'
outputPath = '../Output/'

#Input Raster and Vector Paths
bandList = [band for band in os.listdir(inputPath) if band[-4:]=='.TIF']
bandList

['LC08_L1TP_029047_20190203_20190206_01_T1_B10_c1.TIF',
 'LC08_L1TP_029047_20190203_20190206_01_T1_B11_c1.TIF',
 'LC08_L1TP_029047_20190203_20190206_01_T1_B1_c1.TIF',
 'LC08_L1TP_029047_20190203_20190206_01_T1_B2_c1.TIF',
 'LC08_L1TP_029047_20190203_20190206_01_T1_B3_c1.TIF',
 'LC08_L1TP_029047_20190203_20190206_01_T1_B4_c1.TIF',
 'LC08_L1TP_029047_20190203_20190206_01_T1_B5_c1.TIF',
 'LC08_L1TP_029047_20190203_20190206_01_T1_B6_c1.TIF',
 'LC08_L1TP_029047_20190203_20190206_01_T1_B7_c1.TIF',
 'LC08_L1TP_029047_20190203_20190206_01_T1_B8_c1.TIF',
 'LC08_L1TP_029047_20190203_20190206_01_T1_B9_c1.TIF',
 'LC08_L1TP_029047_20190203_20190206_01_T1_BQA_c1.TIF']

#Shapefile of Area of Influence
shp_clip = '../Shp/AOI_1.shp'

Warp Rasters

We clip all the selected raster files with the Warp option from GDAL

for band in bandList:
    print(outputPath + band[:-4]+'_c2'+band[-4:])
    options = gdal.WarpOptions(cutlineDSName=shp_clip,cropToCutline=True)
    outBand = gdal.Warp(srcDSOrSrcDSTab=inputPath + band,
                        destNameOrDestDS=outputPath + band[:-4]+'_c2'+band[-4:],
                        options=options)
    outBand= None

../Output/LC08_L1TP_029047_20190203_20190206_01_T1_B10_c1_c2.TIF
../Output/LC08_L1TP_029047_20190203_20190206_01_T1_B11_c1_c2.TIF
../Output/LC08_L1TP_029047_20190203_20190206_01_T1_B1_c1_c2.TIF
../Output/LC08_L1TP_029047_20190203_20190206_01_T1_B2_c1_c2.TIF
../Output/LC08_L1TP_029047_20190203_20190206_01_T1_B3_c1_c2.TIF
../Output/LC08_L1TP_029047_20190203_20190206_01_T1_B4_c1_c2.TIF
../Output/LC08_L1TP_029047_20190203_20190206_01_T1_B5_c1_c2.TIF
../Output/LC08_L1TP_029047_20190203_20190206_01_T1_B6_c1_c2.TIF
../Output/LC08_L1TP_029047_20190203_20190206_01_T1_B7_c1_c2.TIF
../Output/LC08_L1TP_029047_20190203_20190206_01_T1_B8_c1_c2.TIF
../Output/LC08_L1TP_029047_20190203_20190206_01_T1_B9_c1_c2.TIF
../Output/LC08_L1TP_029047_20190203_20190206_01_T1_BQA_c1_c2.TIF