diff --git a/Disp/RenderingCanvas.cs b/Disp/RenderingCanvas.cs
index 3602314..d8511c9 100644
--- a/Disp/RenderingCanvas.cs
+++ b/Disp/RenderingCanvas.cs
@@ -253,7 +253,6 @@ namespace Hi.Wpf.Disp
         #endregion
 
         #region DispEngine_Rendering
-        private byte[] PreImageBgra { get; set; }
         /// <summary>
         /// Handles the buffer swapped event from DispEngine
         /// </summary>
@@ -262,12 +261,7 @@ namespace Hi.Wpf.Disp
             if (data == null)
                 return;
 
-            //since the treatment is different from Razor version, 
-            //the image checking mechanism cannot be set in DispEngine.
             Span<byte> bgra = new Span<byte>(data, w * h * 4);
-            if (PreImageBgra != null && bgra.SequenceEqual(PreImageBgra))
-                return;
-            PreImageBgra = bgra.ToArray();
 
             // Copy pixel data from DispEngine
             int n = w * h * 4;
diff --git a/Hi.Wpf.csproj b/Hi.Wpf.csproj
index 935974b..671b5a0 100644
--- a/Hi.Wpf.csproj
+++ b/Hi.Wpf.csproj
@@ -12,7 +12,7 @@
 			HiAPI wpf canvas.
 		</Description>
     <Configurations>Debug;Release</Configurations>
-    <VersionBuild>24</VersionBuild>
+    <VersionBuild>25</VersionBuild>
     <VersionPrefix>3.1.$(VersionBuild)</VersionPrefix>
     <PackageTags>HiAPI</PackageTags>
     <RuntimeIdentifiers>win-x64</RuntimeIdentifiers>