The Watermarked property returns True if the bitmap has a watermark.
Examples:
The following VBA example displays the number of bitmaps that have a watermark.
Sub Test()
Dim s As Shape, n As Long
n = 0
For Each s In ActivePage.Shapes
If s.Type = cdrBitmapShape Then
If s.Bitmap.Watermarked Then n = n + 1
End If
Next s
MsgBox "There are " & n & " watermarked bitmaps"
End Sub