internal Scanline(FIBITMAP dib, int scanline, int length) : base(FreeImage.GetScanLine(dib, scanline), length) { if (dib.IsNull) { throw new ArgumentNullException("dib"); } if ((scanline < 0) || (scanline >= FreeImage.GetHeight(dib))) { throw new ArgumentOutOfRangeException("scanline"); } }