Added extensions for generic image

HPPH/PixelHelper.Average.cs

@@ -26,6 +26,10 @@ public static partial class PixelHelper
         }
     }
 
+    public static T Average<T>(this IImage<T> image)
+        where T : struct, IColor
+        => image.AsRefImage().Average();
+
     public static T Average<T>(this RefImage<T> image)
         where T : struct, IColor
     {

HPPH/PixelHelper.MinMax.cs

@@ -27,6 +27,10 @@ public static unsafe partial class PixelHelper
         }
     }
 
+    public static IMinMax MinMax<T>(this IImage<T> image)
+        where T : struct, IColor
+        => image.AsRefImage().MinMax();
+
     public static IMinMax MinMax<T>(this RefImage<T> image)
         where T : struct, IColor
     {

HPPH/PixelHelper.Quantize.cs

@@ -25,6 +25,10 @@ public static partial class PixelHelper
         }
     }
 
+    public static T[] CreateColorPalette<T>(this IImage<T> image, int paletteSize)
+        where T : unmanaged, IColor
+        => image.AsRefImage().CreateColorPalette(paletteSize);
+
     public static T[] CreateColorPalette<T>(this RefImage<T> image, int paletteSize)
         where T : unmanaged, IColor
     {

HPPH/PixelHelper.Sum.cs

@@ -28,6 +28,10 @@ public static unsafe partial class PixelHelper
         }
     }
 
+    public static ISum Sum<T>(this IImage<T> image)
+        where T : struct, IColor
+        => image.AsRefImage().Sum();
+
     public static ISum Sum<T>(this RefImage<T> image)
         where T : struct, IColor
     {