VBA Help - image resizing

[Carlab49]

In my spreadsheet, the VBA is set to display & resize an image in D4, based on the values entered in A1 (w) and A2 (h), this is the code used:

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$A$1" Then
Shapes("Group 10").Width = Target.Value / 10
End If
If Target.Address = "$A$2" Then
Shapes("Group 10").Height = Target.Value / 10
End If
End Sub

What i would like to do is ensure the image does not exceed the cell (D4) regardless of the height & width values - so resize locking the aspect ratio but keeping it within the cell.

Can someone help me please