You can apply any of the available formatting parameters to the image - here the height is set to 0.5":
Code:
Private Sub UserFormImageToBM(strbmName As String, oImage As Object)
'Graham Mayor - https://www.gmayor.com
'UserformImageToBM "bookmarkName", Image1.Picture
Dim oRng As Range
Dim TempFile As String
Dim oShape As InlineShape
Dim FSO As Object
Set FSO = CreateObject("Scripting.FileSystemObject")
TempFile = Replace(FSO.GetTempName, "tmp", "bmp")
SavePicture oImage, TempFile
With ActiveDocument
On Error GoTo lbl_Exit
Set oRng = .Bookmarks(strbmName).Range
oRng.Text = ""
Set oShape = oRng.InlineShapes.AddPicture _
(Filename:=TempFile, LinkToFile:=False, _
SaveWithDocument:=True)
With oShape
.LockAspectRatio = msoTrue
.Height = InchesToPoints(0.5)
End With
oRng.End = oRng.End + 1
oRng.Bookmarks.Add strbmName
End With
Kill TempFile
lbl_Exit:
Set FSO = Nothing
Set oRng = Nothing
Exit Sub
End Sub