'円領域の反転
Private Sub Command1_Click()
Dim hRgn As Long
'リージョンの作成
hRgn = CreateEllipticRgn(0, 0, 100, 100)
Picture1.Picture = LoadPicture("c:\pic\test.bmp")
InvertRgn Picture1.hDC, hRgn
'後処理
DeleteObject hRgn
End Sub