ENH: Let file readers interpret CHAR enum as signed char

N-Dekker · hjmjohnson · commit 180481bf2be7 · 2025-07-10T07:04:42.000-05:00
Let ImageFileReader, MeshFileReader, and VideoFileReader interpret
`IOComponentEnum::CHAR` as `signed char`, instead of `char`. This ensures
that 8-bits signed data files are properly interpreted.
diff --git a/Modules/IO/ImageBase/include/itkImageFileReader.hxx b/Modules/IO/ImageBase/include/itkImageFileReader.hxx
@@ -482,7 +482,7 @@ ImageFileReader<TOutputImage, ConvertPixelTraits>::DoConvertBuffer(const void *
   {
   }
   ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::UCHAR, unsigned char)
-  ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, char)
+  ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, signed char)
   ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::USHORT, unsigned short)
   ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::SHORT, short)
   ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::UINT, unsigned int)
diff --git a/Modules/IO/MeshBase/include/itkMeshFileReader.hxx b/Modules/IO/MeshBase/include/itkMeshFileReader.hxx
@@ -703,7 +703,7 @@ MeshFileReader<TOutputMesh, ConvertPointPixelTraits, ConvertCellPixelTraits>::Co
   {
   }
   ITK_CONVERT_POINT_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::UCHAR, unsigned char)
-  ITK_CONVERT_POINT_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, char)
+  ITK_CONVERT_POINT_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, signed char)
   ITK_CONVERT_POINT_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::USHORT, unsigned short)
   ITK_CONVERT_POINT_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::SHORT, short)
   ITK_CONVERT_POINT_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::UINT, unsigned int)
@@ -778,7 +778,7 @@ MeshFileReader<TOutputMesh, ConvertPointPixelTraits, ConvertCellPixelTraits>::Co
   {
   }
   ITK_CONVERT_CELL_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::UCHAR, unsigned char)
-  ITK_CONVERT_CELL_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, char)
+  ITK_CONVERT_CELL_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, signed char)
   ITK_CONVERT_CELL_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::USHORT, unsigned short)
   ITK_CONVERT_CELL_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::SHORT, short)
   ITK_CONVERT_CELL_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::UINT, unsigned int)
diff --git a/Modules/Video/IO/include/itkVideoFileReader.hxx b/Modules/Video/IO/include/itkVideoFileReader.hxx
@@ -274,7 +274,7 @@ VideoFileReader<TOutputVideoStream>::DoConvertBuffer(const void * inputData, Fra
   {
   }
   ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::UCHAR, unsigned char)
-  ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, char)
+  ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, signed char)
   ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::USHORT, unsigned short)
   ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::SHORT, short)
   ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::UINT, unsigned int)

Original file line number	Diff line number	Diff line change
`@@ -482,7 +482,7 @@ ImageFileReader<TOutputImage, ConvertPixelTraits>::DoConvertBuffer(const void *`
`482`	`482`	`{`
`483`	`483`	`}`
`484`	`484`	`ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::UCHAR, unsigned char)`
`485`		`- ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, char)`
	`485`	`+ ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, signed char)`
`486`	`486`	`ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::USHORT, unsigned short)`
`487`	`487`	`ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::SHORT, short)`
`488`	`488`	`ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::UINT, unsigned int)`
Original file line number	Diff line number	Diff line change
`@@ -703,7 +703,7 @@ MeshFileReader<TOutputMesh, ConvertPointPixelTraits, ConvertCellPixelTraits>::Co`
`703`	`703`	`{`
`704`	`704`	`}`
`705`	`705`	`ITK_CONVERT_POINT_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::UCHAR, unsigned char)`
`706`		`- ITK_CONVERT_POINT_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, char)`
	`706`	`+ ITK_CONVERT_POINT_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, signed char)`
`707`	`707`	`ITK_CONVERT_POINT_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::USHORT, unsigned short)`
`708`	`708`	`ITK_CONVERT_POINT_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::SHORT, short)`
`709`	`709`	`ITK_CONVERT_POINT_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::UINT, unsigned int)`
`@@ -778,7 +778,7 @@ MeshFileReader<TOutputMesh, ConvertPointPixelTraits, ConvertCellPixelTraits>::Co`
`778`	`778`	`{`
`779`	`779`	`}`
`780`	`780`	`ITK_CONVERT_CELL_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::UCHAR, unsigned char)`
`781`		`- ITK_CONVERT_CELL_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, char)`
	`781`	`+ ITK_CONVERT_CELL_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, signed char)`
`782`	`782`	`ITK_CONVERT_CELL_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::USHORT, unsigned short)`
`783`	`783`	`ITK_CONVERT_CELL_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::SHORT, short)`
`784`	`784`	`ITK_CONVERT_CELL_PIXEL_BUFFER_IF_BLOCK(IOComponentEnum::UINT, unsigned int)`
Original file line number	Diff line number	Diff line change
`@@ -274,7 +274,7 @@ VideoFileReader<TOutputVideoStream>::DoConvertBuffer(const void * inputData, Fra`
`274`	`274`	`{`
`275`	`275`	`}`
`276`	`276`	`ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::UCHAR, unsigned char)`
`277`		`- ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, char)`
	`277`	`+ ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::CHAR, signed char)`
`278`	`278`	`ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::USHORT, unsigned short)`
`279`	`279`	`ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::SHORT, short)`
`280`	`280`	`ITK_CONVERT_BUFFER_IF_BLOCK(IOComponentEnum::UINT, unsigned int)`