Private Declare Function GetWindowDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function GetPixel Lib "gdi32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long) As Long
Private Declare Function CreateRectRgn Lib "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Private Declare Function CombineRgn Lib "gdi32" (ByVal hDestRgn As Long, ByVal hSrcRgn1 As Long, ByVal hSrcRgn2 As Long, ByVal nCombineMode As Long) As Long
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Private Declare Function SetWindowRgn Lib "user32" (ByVal hwnd As Long, ByVal hRgn As Long, ByVal bRedraw As Boolean) As Long

Public Sub BackgroundTransparent(Objet As Object)
    Dim CouleurBackground As Long
    Dim hdcObjet As Long, RectFinal As Long, NewRect As Long
    Dim x As Integer, y As Integer
    
    On Error Resume Next
        hdcObjet = GetWindowDC(Objet.hwnd)
        CouleurBackground = GetPixel(hdcObjet, 0, 0)
    
        If CouleurBackground = -1 Then Exit Sub
        Objet.BackColor = CouleurBackground
        RectFinal = CreateRectRgn(0, 0, Objet.width, Objet.height)
    
        For y = 0 To Objet.height
            For x = 0 To Objet.width
                If GetPixel(hdcObjet, x, y) = CouleurBackground Then
                    NewRect = CreateRectRgn(x, y, x + 1, y + 1)
                    CombineRgn RectFinal, RectFinal, NewRect, 4
                    DeleteObject (NewRect)
                End If
            Next x
            x = 0
        Next y
    
        SetWindowRgn Objet.hwnd, RectFinal, True
        DeleteObject (RectFinal)
End Sub