wxCHECK_MSG( image.Ok(), FALSE, wxT("invalid image") )
wxCHECK_MSG( depth == -1 || depth == 1, FALSE, wxT("invalid bitmap depth") )
wxCHECK_MSG( image.Ok(), FALSE, wxT("invalid image") )
wxCHECK_MSG( depth == -1 || depth == 1, FALSE, wxT("invalid bitmap depth") )