r1730, https://code.google.com/p/aforge/source/detail?r=1730

Fixes Issue 27 : Image statistics reports negative mean value for big
images
Updated calculation of mean in AForge.Math.Statistics to use double
precision numbers internally to avoid integers' overflow.

Sources/Math/Statistics.cs

@@ -47,15 +47,15 @@ public static class Statistics
         public static double Mean( int[] values )
         {
             int     hits;
-            long    total = 0;
+            double  total = 0;
             double  mean = 0;
 
             // for all values
             for ( int i = 0, n = values.Length; i < n; i++ )
             {
                 hits = values[i];
                 // accumulate mean
-                mean += i * hits;
+                mean += (double) i * hits;
                 // accumalate total
                 total += hits;
             }