Hola,
Esto parece funcionar bien:
Código Delphi
[-]
procedure TForm1.Button1Click(Sender: TObject);
begin
Image1.Transparent := true;
Image1.Picture.Bitmap.TransparentMode := tmAuto;
try
Image1.Picture.Bitmap.Assign(Clipboard);
except
on E: EInvalidGraphic do
begin
ShowMessage(E.Message);
raise;
end;
end;
end;