diff --git a/ArcFormats/ArcFormats.csproj b/ArcFormats/ArcFormats.csproj
index c5b0819d..c474cc02 100644
--- a/ArcFormats/ArcFormats.csproj
+++ b/ArcFormats/ArcFormats.csproj
@@ -70,6 +70,7 @@
+
diff --git a/ArcFormats/Silky/ImageMSK.cs b/ArcFormats/Silky/ImageMSK.cs
new file mode 100644
index 00000000..39328a23
--- /dev/null
+++ b/ArcFormats/Silky/ImageMSK.cs
@@ -0,0 +1,276 @@
+//! \file ImageMSK.cs
+//! \date Sat Oct 17 09:33:34 2015
+//! \brief Silky's bitmap mask.
+//
+// Copyright (C) 2015 by morkt
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+using GameRes.Utility;
+using System;
+using System.ComponentModel.Composition;
+using System.IO;
+using System.Windows.Media;
+
+namespace GameRes.Formats.Silky
+{
+ [Export(typeof(ImageFormat))]
+ public class RmskFormat : ImageFormat
+ {
+ public override string Tag { get { return "RMSK/SILKY'S"; } }
+ public override string Description { get { return "Silky's bitmap mask format"; } }
+ public override uint Signature { get { return 0x6B736D52; } } // 'Rmsk'
+
+ public RmskFormat ()
+ {
+ Extensions = new string[] { "msk" };
+ }
+
+ public override ImageMetaData ReadMetaData (Stream stream)
+ {
+ var header = new byte[12];
+ if (12 != stream.Read (header, 0, 12))
+ return null;
+ return new ImageMetaData
+ {
+ Width = LittleEndian.ToUInt16 (header, 8),
+ Height = LittleEndian.ToUInt16 (header, 10),
+ OffsetX = LittleEndian.ToInt16 (header, 4),
+ OffsetY = LittleEndian.ToInt16 (header, 6),
+ BPP = 8,
+ };
+ }
+
+ public override ImageData Read (Stream stream, ImageMetaData info)
+ {
+ using (var reader = new RmskReader (stream, info))
+ {
+ reader.Unpack();
+ return ImageData.CreateFlipped (info, PixelFormats.Gray8, null, reader.Data, (int)info.Width);
+ }
+ }
+
+ public override void Write (Stream file, ImageData image)
+ {
+ throw new System.NotImplementedException ("RmskFormat.Write not implemented");
+ }
+ }
+
+ internal sealed class RmskReader : IDisposable
+ {
+ MsbBitStream m_input;
+ byte[] m_output;
+ int m_flag;
+ int m_width;
+ int m_height;
+
+ public byte[] Data { get { return m_output; } }
+
+ public RmskReader (Stream input, ImageMetaData info)
+ {
+ input.Position = 0xC;
+ m_flag = input.ReadByte();
+ if (-1 == m_flag)
+ throw new EndOfStreamException();
+ input.Position = 0xE;
+ m_input = new MsbBitStream (input, true);
+ m_width = (int)info.Width;
+ m_height = (int)info.Height;
+ m_output = new byte[m_width*m_height];
+ }
+
+ public void Unpack ()
+ {
+ if (0 == (m_flag & 1))
+ UnpackV0();
+ else
+ UnpackV1();
+ }
+
+ void UnpackV0 ()
+ {
+ int line = m_width * (m_height - 1);
+ for (int h = 0; h < m_height; ++h)
+ {
+ int dst = line;
+ int column = m_width;
+ while (column > 0)
+ {
+ if (0 == m_input.GetNextBit())
+ {
+ int src;
+ int count;
+ if (1 == m_input.GetNextBit())
+ {
+ if (0 == m_input.GetNextBit())
+ {
+ src = dst + OffsetTable8[m_input.GetBits (3)];
+ }
+ else
+ {
+ src = m_width + dst + OffsetTable16[m_input.GetBits (4)];
+ }
+ }
+ else
+ {
+ src = dst;
+ if (1 == m_input.GetNextBit())
+ {
+ src += m_width * (m_input.GetNextBit() + 2);
+ }
+ else
+ {
+ src += m_width * (m_input.GetBits (2) + 4);
+ }
+ src += OffsetTable16[m_input.GetBits (4)];
+ }
+ if (1 == m_input.GetNextBit())
+ {
+ count = m_input.GetNextBit() + 2;
+ }
+ else if (1 == m_input.GetNextBit())
+ {
+ count = m_input.GetBits (2) + 4;
+ }
+ else if (1 == m_input.GetNextBit())
+ {
+ count = m_input.GetBits (3) + 8;
+ }
+ else if (1 == m_input.GetNextBit())
+ {
+ count = m_input.GetBits (6) + 16;
+ }
+ else if (1 == m_input.GetNextBit())
+ {
+ count = m_input.GetBits (8) + 80;
+ }
+ else
+ {
+ count = m_input.GetBits (10) + 336;
+ }
+ for (int i = 0; i < count; ++i)
+ {
+ m_output[dst++] = m_output[src++];
+ }
+ column -= count;
+ }
+ else
+ {
+ m_output[dst++] = (byte)m_input.GetBits (8);
+ --column;
+ }
+ }
+ line -= m_width;
+ }
+ }
+
+ void UnpackV1 ()
+ {
+ int column = m_width * (m_height - 1);
+ for (int x = 0; x < m_width; ++x)
+ {
+ int dst = column;
+ int line = m_height;
+ while (line > 0)
+ {
+ if (0 != m_input.GetNextBit())
+ {
+ m_output[dst] = (byte)m_input.GetBits (8);
+ dst -= m_width;
+ --line;
+ }
+ else
+ {
+ int src;
+ if (1 == m_input.GetNextBit())
+ {
+ if (0 == m_input.GetNextBit())
+ {
+ src = dst - m_width * OffsetTable8[m_input.GetBits (3)];
+ }
+ else
+ {
+ src = dst - 1 - m_width * OffsetTable16[m_input.GetBits (4)];
+ }
+ }
+ else if (1 == m_input.GetNextBit())
+ {
+ int n = dst - 2 - m_input.GetNextBit();
+ src = n - m_width * OffsetTable16[m_input.GetBits (4)];
+ }
+ else
+ {
+ int n = dst - 4 - m_input.GetBits (2);
+ src = n - m_width * OffsetTable16[m_input.GetBits (4)];
+ }
+ int count;
+ if (1 == m_input.GetNextBit())
+ {
+ count = m_input.GetBits (1) + 2;
+ }
+ else if (1 == m_input.GetNextBit())
+ {
+ count = m_input.GetBits (2) + 4;
+ }
+ else if (1 == m_input.GetNextBit())
+ {
+ count = m_input.GetBits (3) + 8;
+ }
+ else if (1 == m_input.GetNextBit())
+ {
+ count = m_input.GetBits (6) + 16;
+ }
+ else if (1 == m_input.GetNextBit())
+ {
+ count = m_input.GetBits (8) + 80;
+ }
+ else
+ {
+ count = m_input.GetBits (10) + 336;
+ }
+ line -= count;
+ for (int i = 0; i < count; ++i)
+ {
+ m_output[dst] = m_output[src];
+ src -= m_width;
+ dst -= m_width;
+ }
+ }
+ }
+ ++column;
+ }
+ }
+
+ static int[] OffsetTable8 = { -1, -2, -4, -6, -8, -12, -16, -20 };
+ static int[] OffsetTable16 = { -20, -16, -12, -8, -6, -4, -2, -1, 0, 1, 2, 4, 6, 8, 12, 16 };
+
+ #region IDisposable Members
+ bool _disposed = false;
+ public void Dispose ()
+ {
+ if (!_disposed)
+ {
+ m_input.Dispose();
+ _disposed = true;
+ }
+ }
+ #endregion
+ }
+}