From 65cd1b0bc92f57e6ba1c504b9eb387b6fe1092ba Mon Sep 17 00:00:00 2001
From: "Hans J. Johnson" <hans-johnson@uiowa.edu>
Date: Wed, 16 Sep 2026 09:37:57 -0500
Subject: [PATCH] COMP: Use itk::IOComponentEnum and include vnl_svd.h (ITK 6)

ITK removes itk::ImageIOBase::IOComponentType when ITK_LEGACY_REMOVE is
ON, which ITK forces whenever it is built with wrapping enabled. The
namespace-scope itk::IOComponentEnum is present in both ITK 5.4 and
ITK 6, so this spelling builds against either.

vtkPlusProbeCalibrationOptimizerAlgo used vnl_svd without including it,
relying on an ITK header to pull it in transitively; ITK 6 no longer
does. Include it directly.
---
 .../vtkPlusProbeCalibrationOptimizerAlgo.cxx                    | 2 ++
 src/PlusCommon/PlusCommon.h                                     | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/PlusCalibration/vtkProbeCalibrationAlgo/vtkPlusProbeCalibrationOptimizerAlgo.cxx b/src/PlusCalibration/vtkProbeCalibrationAlgo/vtkPlusProbeCalibrationOptimizerAlgo.cxx
index 42d9e5ad5..5082d6284 100644
--- a/src/PlusCalibration/vtkProbeCalibrationAlgo/vtkPlusProbeCalibrationOptimizerAlgo.cxx
+++ b/src/PlusCalibration/vtkProbeCalibrationAlgo/vtkPlusProbeCalibrationOptimizerAlgo.cxx
@@ -18,6 +18,8 @@ See License.txt for details.
 
 #include "vtksys/SystemTools.hxx"
 
+#include <vnl/algo/vnl_svd.h>
+
 #include "itkPowellOptimizer.h"
 #include "itkScaleVersor3DTransform.h"
 #include "itkSimilarity3DTransform.h"
diff --git a/src/PlusCommon/PlusCommon.h b/src/PlusCommon/PlusCommon.h
index 7c6580576..7321f462f 100644
--- a/src/PlusCommon/PlusCommon.h
+++ b/src/PlusCommon/PlusCommon.h
@@ -51,7 +51,7 @@ class vtkXMLDataElement;
 
 namespace PlusCommon
 {
-  typedef itk::ImageIOBase::IOComponentType ITKScalarPixelType;
+  typedef itk::IOComponentEnum ITKScalarPixelType;
   typedef int VTKScalarPixelType;
   typedef int IGTLScalarPixelType;