SHIT THAT I MAKE

    Function Submap(mapping As Byte(), x As Integer, y As Integer, sizeWidth As Integer, sizeHeight As Integer, imageSizeWidth As Integer, imageSizeHeight As Integer) As Byte()
        Dim mapSplit As New List(Of Byte)
        For y1 = y / 4 * (imageSizeWidth / 8) To y / 4 * (imageSizeWidth / 8) + (sizeHeight / 8) * (imageSizeWidth / 8) * 2 - 1 Step (imageSizeWidth / 8) * 2
            For x1 = x / 8 To x / 8 + sizeWidth / 8 - 1
                mapSplit.Add(mapping(y1 + x1 * 2))
                mapSplit.Add(mapping(y1 + x1 * 2 + 1))
            Next
        Next
        Return mapSplit.ToArray
    End Function