switch classes still using the cos object approach to the tokenization approach initally used for parsing cmap files.

src/UglyToad.PdfPig/Tokenization/Tokens/StreamToken.cs

@@ -1,7 +1,14 @@
 namespace UglyToad.PdfPig.Tokenization.Tokens
 {
+    using System;
+    using Filters;
+
     internal class StreamToken : IDataToken<byte[]>
     {
+        private readonly object lockObject = new object();
+
+        private byte[] decodedBytes;
+
         public DictionaryToken StreamDictionary { get; }
 
         public byte[] Data { get; }
@@ -11,5 +18,28 @@
             StreamDictionary = streamDictionary;
             Data = data;
         }
+
+        public byte[] Decode(IFilterProvider filterProvider)
+        {
+            lock (lockObject)
+            {
+                if (decodedBytes != null)
+                {
+                    return decodedBytes;
+                }
+                
+                var filters = filterProvider.GetFilters(StreamDictionary);
+
+                var transform = Data;
+                for (var i = 0; i < filters.Count; i++)
+                {
+                    transform = filters[i].Decode(transform, StreamDictionary, i);
+                }
+
+                decodedBytes = transform;
+
+                return transform;
+            }
+        }
     }
 }