Sometime I run into errors that seem to make no sense and it takes me a while to find the answer as to why. Such is the case with this error. I wrote a routine in VB.NET to split a multi-page tiff file. Every once in a while, I would get this less than helpful error: “A generic error occurred in GDI+.” when calling the Image.Save() function.

Thanks to another frustrated user that found the solution I was able to see that sometime the folder I was sending files to did not exist. So rather GDI telling me that the save path did not exist it simply threw a generic error. Thanks!

So as long as you’re reading this, I might as well share the function that splits a multi-page tiff file. There are actually two functions. UniqueName is a recursive function that makes sure you don’t overwrite an existing file.

Shared Function SplitTiffFile(ByVal filePath As String, ByVal cachePath As String, Optional ByRef filePaths() As String = Nothing) As Boolean
Dim objImage As Image = Image.FromFile(filePath)
Dim objGuid As Guid = (objImage.FrameDimensionsList(0))
Dim objDimension As System.Drawing.Imaging.FrameDimension = New System.Drawing.Imaging.FrameDimension(objGuid)
Dim Pages As Integer = objImage.GetFrameCount(objDimension)
Dim Filename As String

For i As Integer = 0 To Pages - 1
objImage.SelectActiveFrame(objDimension, i)
Filename = IO.Path.GetFileNameWithoutExtension(filePath) & "-" & (i + 1).ToString.PadLeft(3, CChar("0")) & ".tif"
ReDim Preserve filePaths(i)
filePaths(i) = IO.Path.Combine(cachePath, Filename)
filePaths(i) = UniqueName(filePaths(i))
If Not IO.Directory.Exists(IO.Path.GetDirectoryName(filePaths(i))) Then
End If
objImage.Save(filePaths(i), Imaging.ImageFormat.Tiff)
End Function

Shared Function UniqueName(ByVal Filename As String) As String
If IO.File.Exists(Filename) Then
' Append ~### to the end of the file name
Dim name, ext, newFilename As String
Dim regex As New Regex("~([0-9]{3})$")
Dim mc As MatchCollection
Dim matchVal As Integer

name = IO.Path.GetFileNameWithoutExtension(Filename)
ext = IO.Path.GetExtension(Filename)
If regex.IsMatch(name) Then
mc = regex.Matches(name)
name = name.Substring(0, name.Length - 4)
matchVal = CInt(mc.Item(0).Value.Substring(1)) + 1
name = name & "~" & CStr(matchVal).PadLeft(3, CChar("0"))
name = name & "~001"
End If
newFilename = IO.Path.Combine(IO.Path.GetDirectoryName(Filename), name & ext)

' Recursion
Filename = UniqueName(newFilename)
Return Filename
Return Filename
End If
End Function