BandMath¶
Outputs a monoband image which is the result of a mathematical operation on several multi-band images.
Description¶
This application performs a mathematical operation on several multi-band images and outputs the result into a monoband image. The given expression is computed at each pixel position. Evaluation of the mathematical formula is done by the muParser library.
The formula can be written using:
numerical values ( 2.3, -5, 3.1e4, …)
variables containing pixel values (e.g.
im2b3is the pixel value in 2nd image, 3rd band)binary operators:
+addition,-subtraction,*multiplication,/division^raise x to the power of y<less than,>greater than,<=less or equal,>=greater or equal==equal,!=not equal||logical or,&&logical andif-then-else operator:
(condition ? value_true : value_false)
functions:
exp(),log(),sin(),cos(),min(),max(), …
The full list of features and operators is available on the muParser website [1].
Parameters¶
Input image list -il image1 image2... Mandatory
Image list of operands to the mathematical expression.
Output Image -out image [dtype] Mandatory
Output image which is the result of the mathematical expressions on input image list operands.
Expression -exp string Mandatory
The muParser mathematical expression to apply on input images.
Available RAM (MB) -ram int Default value: 256
Available memory for processing (in MB).
Examples¶
From the command-line:
otbcli_BandMath -il verySmallFSATSW_r.tif verySmallFSATSW_nir.tif verySmallFSATSW.tif -out apTvUtBandMathOutput.tif -exp "cos( im1b1 ) > cos( im2b1 ) ? im3b1 : im3b2"
From Python:
import otbApplication
app = otbApplication.Registry.CreateApplication("BandMath")
app.SetParameterStringList("il", ['verySmallFSATSW_r.tif', 'verySmallFSATSW_nir.tif', 'verySmallFSATSW.tif'])
app.SetParameterString("out", "apTvUtBandMathOutput.tif")
app.SetParameterString("exp", "cos( im1b1 ) > cos( im2b1 ) ? im3b1 : im3b2")
app.ExecuteAndWriteOutput()