.. _ComputeModulusAndPhase: 

ComputeModulusAndPhase
======================





This application computes the modulus and the phase of a complex SAR image or an image with 2 components (real and imaginary parts).

Description
-----------

This application computes the modulus and the phase of a complex SAR image. The input should be a single band image with complex pixels or a 2 bands image (real and imaginary components in separate bands).

This application has several output images and supports "multi-writing". Instead of computing and writing each image independently, the streamed image blocks are written in a synchronous way for each output. The output images will be computed strip by strip, using the available RAM to compute the strip size, and a user defined streaming mode can be specified using the streaming extended filenames (type, mode and value). Note that multi-writing can be disabled using the multi-write extended filename option: &multiwrite=false, in this case the output images will be written one by one. Note that multi-writing is not supported for MPI writers.

Parameters
----------

.. contents:: :local:

.. |br| raw:: html

   <br />

.. |em| raw:: html

   &emsp;

**Input Image** :code:`-in image` *Mandatory* |br|
Input image (complex single band or 2 bands (real/imaginary parts))

**Modulus** :code:`-modulus image [dtype]` *Mandatory* |br|
Modulus of the input image computes with the
following formula: :math:`\sqrt{real*real + imag*imag}` where real and imag 
are respectively the real and the imaginary part of the input complex image.


**Phase** :code:`-phase image [dtype]` *Mandatory* |br|
Phase of the input image computes with the following formula:
:math:`\tan^{-1}(\frac{imag}{real})` where real and imag are respectively the real and
the imaginary part of the input complex image.

**Available RAM (MB)** :code:`-ram int` *Default value: 256* |br|
Available memory for processing (in MB).



Examples
--------

From the command-line:

.. code-block:: bash

    otbcli_ComputeModulusAndPhase -in monobandComplexFloat.tif -modulus modulus.tif -phase phase.tif


From Python:

.. code-block:: python

	import otbApplication

	app = otbApplication.Registry.CreateApplication("ComputeModulusAndPhase")

	app.SetParameterString("in", "monobandComplexFloat.tif")
	app.SetParameterString("modulus", "modulus.tif")
	app.SetParameterString("phase", "phase.tif")

	app.ExecuteAndWriteOutput()



Limitations
-----------

The application takes as input single band image with complex pixels or a 2 bands image (real and imaginary part in separate bands).

See also
--------

| :ref:`Despeckle`, :ref:`SARPolarMatrixConvert`, :ref:`SARPolarSynth`