diff --git a/ArcFormats/Palette/ArcCHR.cs b/ArcFormats/Palette/ArcCHR.cs
index cfa0bcd3..dd4a52ad 100644
--- a/ArcFormats/Palette/ArcCHR.cs
+++ b/ArcFormats/Palette/ArcCHR.cs
@@ -179,31 +179,8 @@ namespace GameRes.Formats.Palette
                 var bmp = new RenderTargetBitmap (base_frame.PixelWidth, base_frame.PixelHeight,
                                                   base_frame.DpiX, base_frame.DpiY, PixelFormats.Pbgra32);
                 bmp.Render (visual);
-                var base_info = new ImageMetaData {
-                    Width  = (uint)bmp.PixelWidth,
-                    Height = (uint)bmp.PixelHeight,
-                    BPP    = bmp.Format.BitsPerPixel,
-                };
-                return new BitmapSourceDecoder (bmp, base_info);
+                return new BitmapSourceDecoder (bmp);
             }
         }
     }
-
-    internal class BitmapSourceDecoder : IImageDecoder
-    {
-        public Stream            Source { get { return null; } }
-        public ImageFormat SourceFormat { get { return null; } }
-        public ImageMetaData       Info { get; private set; }
-        public ImageData          Image { get; private set; }
-
-        public BitmapSourceDecoder (BitmapSource bmp, ImageMetaData info)
-        {
-            Info = info;
-            Image = new ImageData (bmp, info);
-        }
-
-        public void Dispose ()
-        {
-        }
-    }
 }
diff --git a/ArcFormats/Tamamo/ArcPCK.cs b/ArcFormats/Tamamo/ArcPCK.cs
index d46f56ee..1930ece7 100644
--- a/ArcFormats/Tamamo/ArcPCK.cs
+++ b/ArcFormats/Tamamo/ArcPCK.cs
@@ -257,26 +257,4 @@ namespace GameRes.Formats.Tamamo
             return key;
         }
     }
-
-    internal class BitmapSourceDecoder : IImageDecoder
-    {
-        public Stream            Source { get { return null; } }
-        public ImageFormat SourceFormat { get { return null; } }
-        public ImageMetaData       Info { get; private set; }
-        public ImageData          Image { get; private set; }
-
-        public BitmapSourceDecoder (BitmapSource bitmap)
-        {
-            Info = new ImageMetaData {
-                Width = (uint)bitmap.PixelWidth,
-                Height = (uint)bitmap.PixelHeight,
-                BPP = bitmap.Format.BitsPerPixel,
-            };
-            Image = new ImageData (bitmap);
-        }
-
-        public void Dispose ()
-        {
-        }
-    }
 }
diff --git a/GameRes/ImageDecoder.cs b/GameRes/ImageDecoder.cs
index 60d5e23f..b415601e 100644
--- a/GameRes/ImageDecoder.cs
+++ b/GameRes/ImageDecoder.cs
@@ -25,6 +25,7 @@
 
 using System;
 using System.IO;
+using System.Windows.Media.Imaging;
 
 namespace GameRes
 {
@@ -165,4 +166,26 @@ namespace GameRes
         }
         #endregion
     }
+
+    public class BitmapSourceDecoder : IImageDecoder
+    {
+        public Stream            Source { get; set; }
+        public ImageFormat SourceFormat { get; set; }
+        public ImageMetaData       Info { get; private set; }
+        public ImageData          Image { get; private set; }
+
+        public BitmapSourceDecoder (BitmapSource bitmap)
+        {
+            Info = new ImageMetaData {
+                Width = (uint)bitmap.PixelWidth,
+                Height = (uint)bitmap.PixelHeight,
+                BPP = bitmap.Format.BitsPerPixel,
+            };
+            Image = new ImageData (bitmap);
+        }
+
+        public void Dispose ()
+        {
+        }
+    }
 }