Principal component analysis

Using QGIS OTB plugin

• In the search engine of the Processing Toolbox, type PCA and select DimensionalityReduction(pca) under Image Filtering of the Orfeo Toolbox.
• Under the Parameter tab, select Multispectral band file as the input layer.
• Select pca under the Algorithm tab.
• Enter 4 as the number of components.
• Specify the directory to save the output file.
• Untick output file after running algorithm (inverse output image) option.
• Click on Run to execute the algorithm.

Using OTB standalone

• Type into the search box of the Windows taskbar: mapla.bat. Click on mapla.bat to open Monteverdi Application Launcher.
• In the search engine of Mapla, type Dimension and double click Dimensionality Reduction.
• Specify a multispectral image as Input Image.
• Specify directory and name for the Output image. Select the output data type float from the pull-down list.
• Select PCA from the drop-down list as Algorithm.
• Enter 4 as number of components.
• Click on Execute.