ENH: Allow to compute modulus and phase from 2 bands scalar image

Summary

The support of complex images in otb applications as improved in version 6.6. There is generic mechanism based on teh ClampImageFilter which allow to go from/to complex or multi-bands scalar images. The only change is to read the input image as ComplexFloatImageType which support both complex image (single band) or image with 2 bands which corresponds to the real and imaginary parts. The documentation of the application has been updated to reflect this modification.

Rationale

Allow to compute modulus and phase from complex single image and 2 bands as it is fully supported by otb filters

Implementation Details

Applications

ComputeModulusAndPhase

Additional notes

Copyright

The copyright owner is CNES and has signed the ORFEO ToolBox Contributor License Agreement.

---

***Check before merging:*** - All discussions are resolved - At least 2 votes from core developers, no vote. - The feature branch is (reasonably) up-to-date with the base branch - Dashboard is green - Copyright owner has signed the ORFEO ToolBox Contributor License Agreement

Modules/Applications/AppSARUtils/app/otbComputeModulusAndPhase.cxx

@@ -20,10 +20,10 @@
 
 #include "otbWrapperApplication.h"
 #include "otbWrapperApplicationFactory.h"
-#include "otbMultiToMonoChannelExtractROI.h"
 
 #include "itkComplexToPhaseImageFilter.h"
 #include "itkComplexToModulusImageFilter.h"
+
 #include "itkMacro.h"
 
 namespace otb
@@ -52,7 +52,6 @@ public:
   itkTypeMacro(ComputeModulusAndPhase, otb::Wrapper::Application);
 
   //typedefs for the application
-  typedef otb::MultiToMonoChannelExtractROI<ComplexFloatVectorImageType::InternalPixelType, ComplexFloatImageType::PixelType> ExtractFilterType;
   typedef itk::ComplexToModulusImageFilter<ComplexFloatImageType, FloatImageType>   ModulusFilterType;
   typedef itk::ComplexToPhaseImageFilter<ComplexFloatImageType, FloatImageType>   PhaseFilterType;
 
@@ -60,23 +59,23 @@ private:
   void DoInit() override
   {
     SetName("ComputeModulusAndPhase");
-    SetDescription("This application computes the modulus and the phase of a complex SAR image.");
+    SetDescription("This application computes the modulus and the phase of a complex SAR image or an image with 2 components (real and imaginary parts).");
 
-    SetDocName("Compute Modulus And Phase");
+    SetDocName("Compute Modulus and Phase");
     SetDocLongDescription(
       "This application computes the modulus and the phase of a "
       "complex SAR image. The input should be a single band image with "
-      "complex pixels."
+      "complex pixels or a 2 bands image (real and imaginary components in separate bands)."
     );
-    SetDocLimitations("The application takes as input single band image with complex pixels.");
+    SetDocLimitations("The application takes as input single band image with complex pixels or a 2 bands image (real and imaginary part in separate bands).");
     SetDocAuthors("Alexia Mondot (alexia.mondot@c-s.fr) and Mickael Savinaud (mickael.savinaud@c-s.fr)");
     SetDocSeeAlso("Despeckle, SARPolarMatrixConvert, SARPolarSynth");
 
     AddDocTag(Tags::SAR);
     AddDocTag(Tags::Manip);
     // Input images
-    AddParameter(ParameterType_InputImage,  "in",   "Input Image");
-    SetParameterDescription("in", "Input image (complex single band)");
+    AddParameter(ParameterType_InputImage, "in", "Input Image");
+    SetParameterDescription("in","Input image (complex single band or 2 bands (real/imaginary parts))");
 
     // Outputs
     AddParameter(ParameterType_OutputImage, "modulus", "Modulus");
@@ -110,26 +109,20 @@ private:
     m_Modulus = ModulusFilterType::New();
     m_Phase = PhaseFilterType::New();
 
-    ComplexFloatVectorImageType::Pointer inImage = GetParameterComplexFloatVectorImage("in");
-
-    if (inImage->GetNumberOfComponentsPerPixel() != 1)
-    {
-        otbAppLogFATAL("Input must be a single band complex image.");
-    }
-
-    // Get first band
-    m_Extract = ExtractFilterType::New();
-    m_Extract->SetInput(inImage);
+    // Read the input as a complex image (with one component) Input with 2
+    // components are also supported (band 1 is interpreted as the real part and
+    // band 2 as the imaginary part VectorImage of complex image are not
+    // supported by the application
+    ComplexFloatImageType::Pointer inImage = GetParameterComplexFloatImage("in");
 
     // Compute modulus and phase
-    m_Modulus->SetInput(m_Extract->GetOutput());
-    m_Phase->SetInput(m_Extract->GetOutput());
+    m_Modulus->SetInput(inImage);
+    m_Phase->SetInput(inImage);
 
-    SetParameterOutputImage("modulus", m_Modulus->GetOutput() );
+    SetParameterOutputImage("modulus", m_Modulus->GetOutput());
     SetParameterOutputImage("phase", m_Phase->GetOutput());
   }
 
-  ExtractFilterType::Pointer m_Extract;
   ModulusFilterType::Pointer m_Modulus;
   PhaseFilterType::Pointer m_Phase;
 };