BUG: Do not refuse to read images of vectors with many components

This was encountered when reading 31-component image which is float on disk, but is being read as double.
InsightSoftwareConsortium · Jan 14, 2022 · 5492689 · 5492689
1 parent df6e287
commit 5492689
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Showing 2 changed files with 46 additions and 3 deletions.
diff --git a/Modules/IO/ImageBase/include/itkConvertPixelBuffer.h b/Modules/IO/ImageBase/include/itkConvertPixelBuffer.h
@@ -139,6 +139,13 @@ class ITK_TEMPLATE_EXPORT ConvertPixelBuffer
                               OutputPixelType * outputData,
                               size_t            size);
 
+  /** This is meant for many component vectors, e.g. converting 31-component float to 31-component double. */
+  static void
+  ConvertVectorToVector(InputPixelType *  inputData,
+                        int               inputNumberOfComponents,
+                        OutputPixelType * outputData,
+                        size_t            size);
+
   /** Convert tensor output. */
   /** Each input is made into a 6 component symmetric pixel */
   static void

diff --git a/Modules/IO/ImageBase/include/itkConvertPixelBuffer.hxx b/Modules/IO/ImageBase/include/itkConvertPixelBuffer.hxx
@@ -146,10 +146,19 @@ ConvertPixelBuffer<InputPixelType, OutputPixelType, OutputConvertTraits>::Conver
       break;
     }
     default:
-      itkGenericExceptionMacro("No conversion available from "
-                               << inputNumberOfComponents
-                               << " components to: " << OutputConvertTraits::GetNumberOfComponents() << " components");
+    {
+      if (inputNumberOfComponents == static_cast<int>(OutputConvertTraits::GetNumberOfComponents()))
+      {
+        ConvertVectorToVector(inputData, inputNumberOfComponents, outputData, size);
+      }
+      else
+      {
+        itkGenericExceptionMacro("No conversion available from " << inputNumberOfComponents << " components to: "
+                                                                 << OutputConvertTraits::GetNumberOfComponents()
+                                                                 << " components");
+      }
       break;
+    }
   }
 }
 
@@ -481,6 +490,33 @@ ConvertPixelBuffer<InputPixelType, OutputPixelType, OutputConvertTraits>::Conver
   }
 }
 
+template <typename InputPixelType, typename OutputPixelType, typename OutputConvertTraits>
+void
+ConvertPixelBuffer<InputPixelType, OutputPixelType, OutputConvertTraits>::ConvertVectorToVector(
+  InputPixelType *  inputData,
+  int               inputNumberOfComponents,
+  OutputPixelType * outputData,
+  size_t            size)
+{
+  int outputNumberOfComponents = OutputConvertTraits::GetNumberOfComponents();
+  int componentCount = std::min(inputNumberOfComponents, outputNumberOfComponents);
+
+  for (size_t i = 0; i < size; ++i)
+  {
+    for (int c = 0; c < componentCount; ++c)
+    {
+      OutputConvertTraits::SetNthComponent(c, *outputData, static_cast<OutputComponentType>(*(inputData + c)));
+    }
+    for (int c = componentCount; c < outputNumberOfComponents; ++c)
+    {
+      OutputConvertTraits::SetNthComponent(c, *outputData, 0); // set the rest of components to zero
+    }
+
+    ++outputData;
+    inputData += inputNumberOfComponents;
+  }
+}
+
 template <typename InputPixelType, typename OutputPixelType, typename OutputConvertTraits>
 void
 ConvertPixelBuffer<InputPixelType, OutputPixelType, OutputConvertTraits>::ConvertTensor6ToTensor6(