Well, one idea would be to insert an auto-shape rectangle over your picture that is 0% transparent, change the border to no border, and then convert it to 100% transparent, as I did with the following macro:
Code:
Sub Macro2()
'
' Macro2 Macro
'
ActiveDocument.Shapes("Rectangle 2").Select
Selection.ShapeRange.Fill.Visible = msoTrue
Selection.ShapeRange.Fill.Solid
Selection.ShapeRange.Fill.ForeColor.RGB = RGB(255, 255, 255)
Selection.ShapeRange.Fill.Transparency = 1#
Selection.ShapeRange.Line.Weight = 0.75
Selection.ShapeRange.Line.DashStyle = msoLineSolid
Selection.ShapeRange.Line.Style = msoLineSingle
Selection.ShapeRange.Line.Transparency = 0#
Selection.ShapeRange.Line.Visible = msoFalse
Selection.ShapeRange.LockAspectRatio = msoFalse
Selection.ShapeRange.Rotation = 0#
Selection.ShapeRange.Left = 6.45
Selection.ShapeRange.Top = 10.05
Selection.ShapeRange.RelativeHorizontalPosition = _
wdRelativeHorizontalPositionColumn
Selection.ShapeRange.RelativeVerticalPosition = _
wdRelativeVerticalPositionParagraph
Selection.ShapeRange.Left = InchesToPoints(-0.01)
Selection.ShapeRange.Top = InchesToPoints(-0.02)
Selection.ShapeRange.LockAnchor = False
Selection.ShapeRange.LayoutInCell = True
Selection.ShapeRange.WrapFormat.AllowOverlap = True
Selection.ShapeRange.WrapFormat.Side = wdWrapBoth
Selection.ShapeRange.WrapFormat.DistanceTop = InchesToPoints(0)
Selection.ShapeRange.WrapFormat.DistanceBottom = InchesToPoints(0)
Selection.ShapeRange.WrapFormat.DistanceLeft = InchesToPoints(0.13)
Selection.ShapeRange.WrapFormat.DistanceRight = InchesToPoints(0.13)
Selection.ShapeRange.WrapFormat.Type = 3
Selection.ShapeRange.ZOrder 4
End Sub
However, please note that the sizes and location are just for the picture I was using - you would have to build your own macro.
Oh, and I used Word 2003, but the idea should still be the same.