diff --git a/src/ImageProcessor.Web/Caching/DiskCache.cs b/src/ImageProcessor.Web/Caching/DiskCache.cs
index 58eb5ea32..fd0778e76 100644
--- a/src/ImageProcessor.Web/Caching/DiskCache.cs
+++ b/src/ImageProcessor.Web/Caching/DiskCache.cs
@@ -66,6 +66,11 @@ namespace ImageProcessor.Web.Caching
         /// </summary>
         private readonly string fullPath;
 
+        /// <summary>
+        /// The querystring containing processing instructions.
+        /// </summary>
+        private readonly string querystring;
+
         /// <summary>
         /// The physical cached path.
         /// </summary>
@@ -87,10 +92,14 @@ namespace ImageProcessor.Web.Caching
         /// <param name="fullPath">
         /// The full path for the image.
         /// </param>
-        public DiskCache(string requestPath, string fullPath)
+        /// <param name="querystring">
+        /// The querystring containing instructions.
+        /// </param>
+        public DiskCache(string requestPath, string fullPath, string querystring)
         {
             this.requestPath = requestPath;
             this.fullPath = fullPath;
+            this.querystring = querystring;
 
             // Get the physical and virtual paths.
             this.GetCachePaths();
@@ -279,7 +288,7 @@ namespace ImageProcessor.Web.Caching
                 // Use an sha1 hash of the full path including the querystring to create the image name.
                 // That name can also be used as a key for the cached image and we should be able to use
                 // The characters of that hash as sub-folders.
-                string parsedExtension = ImageHelpers.GetExtension(this.fullPath);
+                string parsedExtension = ImageHelpers.GetExtension(this.fullPath, this.querystring);
                 string encryptedName = (streamHash + this.fullPath).ToSHA1Fingerprint();
 
                 // Collision rate of about 1 in 10000 for the folder structure.
diff --git a/src/ImageProcessor.Web/Helpers/ImageHelpers.cs b/src/ImageProcessor.Web/Helpers/ImageHelpers.cs
index cfa6186fd..3ba8a56fc 100644
--- a/src/ImageProcessor.Web/Helpers/ImageHelpers.cs
+++ b/src/ImageProcessor.Web/Helpers/ImageHelpers.cs
@@ -11,10 +11,13 @@
 namespace ImageProcessor.Web.Helpers
 {
     using System.IO;
+    using System.Linq;
     using System.Text;
     using System.Text.RegularExpressions;
     using ImageProcessor.Configuration;
     using ImageProcessor.Imaging.Formats;
+    using ImageProcessor.Web.Configuration;
+    using ImageProcessor.Web.Processors;
 
     /// <summary>
     /// The image helpers.
@@ -27,10 +30,9 @@ namespace ImageProcessor.Web.Helpers
         public static readonly string ExtensionRegexPattern = BuildExtensionRegexPattern();
 
         /// <summary>
-        /// The exclude regex for matching things to ignore when parsing image extensions.
-        /// TODO: This is hacky and awful and should go.
+        /// The regex for matching the format to ignore when parsing image extensions.
         /// </summary>
-        private static readonly Regex ExcludeRegex = new Regex(@"(mask|overlay)=[\w+-]+.", RegexOptions.IgnoreCase);
+        private static readonly Regex FormatProcessorRegex = new Regex(@"format=[\w+-]+.", RegexOptions.IgnoreCase);
 
         /// <summary>
         /// The image format regex.
@@ -55,31 +57,52 @@ namespace ImageProcessor.Web.Helpers
         /// <summary>
         /// Returns the correct file extension for the given string input
         /// </summary>
-        /// <param name="input">
+        /// <param name="fullPath">
         /// The string to parse.
         /// </param>
+        /// <param name="queryString">
+        /// The querystring containing instructions.
+        /// </param>
         /// <returns>
         /// The correct file extension for the given string input if it can find one; otherwise an empty string.
         /// </returns>
-        public static string GetExtension(string input)
+        public static string GetExtension(string fullPath, string queryString)
         {
-            // First filter out any troublesome elements.
-            foreach (Match exclude in ExcludeRegex.Matches(input))
+            Match match;
+
+            // First check to see if the format processor is being used and test against that.
+            IWebGraphicsProcessor format = ImageProcessorConfiguration.Instance.GraphicsProcessors
+                                           .First(p => typeof(Format) == p.GetType());
+
+            if (format != null)
             {
-                input = input.Replace(exclude.Value, string.Empty);
+                match = format.RegexPattern.Match(queryString);
+            }
+            else
+            {
+                // Test against the path minus the querystring so any other
+                // processors don't interere.
+                string trimmed = fullPath.Replace(queryString, string.Empty);
+                match = FormatRegex.Match(trimmed);
             }
-
-            Match match = FormatRegex.Match(input);
 
             if (match.Success)
             {
+                string value = match.Value;
+
+                // Clip if format processor match.
+                if (match.Value.Contains("="))
+                {
+                    value = value.Split('=')[1];
+                }
+
                 // Ah the enigma that is the png file.
-                if (match.Value.ToLowerInvariant().EndsWith("png8"))
+                if (value.ToLowerInvariant().EndsWith("png8"))
                 {
                     return "png";
                 }
 
-                return match.Value;
+                return value;
             }
 
             return string.Empty;
diff --git a/src/ImageProcessor.Web/HttpModules/ImageProcessingModule.cs b/src/ImageProcessor.Web/HttpModules/ImageProcessingModule.cs
index f8f8f4bf5..5f15c4e0d 100644
--- a/src/ImageProcessor.Web/HttpModules/ImageProcessingModule.cs
+++ b/src/ImageProcessor.Web/HttpModules/ImageProcessingModule.cs
@@ -145,7 +145,7 @@ namespace ImageProcessor.Web.HttpModules
             this.Dispose(true);
 
             // This object will be cleaned up by the Dispose method.
-            // Therefore, you should call GC.SupressFinalize to
+            // Therefore, you should call GC.SuppressFinalize to
             // take this object off the finalization queue
             // and prevent finalization code for this object
             // from executing a second time.
@@ -269,7 +269,7 @@ namespace ImageProcessor.Web.HttpModules
         {
             HttpRequest request = context.Request;
 
-            // SHould we ignore this request?
+            // Should we ignore this request?
             if (request.RawUrl.ToUpperInvariant().Contains("IPIGNORE=TRUE"))
             {
                 return;
@@ -329,7 +329,7 @@ namespace ImageProcessor.Web.HttpModules
                     string fullPath = string.Format("{0}{1}?{2}", requestPath, parts, queryString);
 
                     // Create a new cache to help process and cache the request.
-                    DiskCache cache = new DiskCache(requestPath, fullPath);
+                    DiskCache cache = new DiskCache(requestPath, fullPath, queryString);
                     string cachedPath = cache.CachedPath;
 
                     // Since we are now rewriting the path we need to check again that the current user has access
diff --git a/src/ImageProcessor/Configuration/NativeBinaryFactory.cs b/src/ImageProcessor/Configuration/NativeBinaryFactory.cs
index 16ab92261..1f939fe5d 100644
--- a/src/ImageProcessor/Configuration/NativeBinaryFactory.cs
+++ b/src/ImageProcessor/Configuration/NativeBinaryFactory.cs
@@ -163,7 +163,7 @@ namespace ImageProcessor.Configuration
             this.Dispose(true);
 
             // This object will be cleaned up by the Dispose method.
-            // Therefore, you should call GC.SupressFinalize to
+            // Therefore, you should call GC.SuppressFinalize to
             // take this object off the finalization queue 
             // and prevent finalization code for this object
             // from executing a second time.
diff --git a/src/ImageProcessor/ImageFactory.cs b/src/ImageProcessor/ImageFactory.cs
index c5ce4f630..8e8a1d396 100644
--- a/src/ImageProcessor/ImageFactory.cs
+++ b/src/ImageProcessor/ImageFactory.cs
@@ -1075,7 +1075,7 @@ namespace ImageProcessor
             this.Dispose(true);
 
             // This object will be cleaned up by the Dispose method.
-            // Therefore, you should call GC.SupressFinalize to
+            // Therefore, you should call GC.SuppressFinalize to
             // take this object off the finalization queue 
             // and prevent finalization code for this object
             // from executing a second time.