diff --git a/rawimage.cpp b/rawimage.cpp
index ed176e5..262f823 100644
--- a/rawimage.cpp
+++ b/rawimage.cpp
@@ -177,10 +177,20 @@ void calcStats(const T *data, size_t n, size_t w, RawImage::Stats &stats)
             statsFunc(data[i*ch + 1], 1);
             statsFunc(data[i*ch + 2], 2);
         }
-        if constexpr(ch == 1)
+    }
+    if constexpr(ch == 1)
+    {
+        size_t h = (n / w) & (SIZE_MAX-1);
+        w &= (SIZE_MAX-1);
+        for(size_t y=0; y<h; y+=2)
         {
-            int bayer = (i % w & 1) + (i / w & 1) + 1;
-            statsFunc(data[i], bayer);
+            for(size_t x=0; x<w; x+=2)
+            {
+               statsFunc(data[y*w+x], 1);
+               statsFunc(data[y*w+x+1], 2);
+               statsFunc(data[(y+1)*w+x], 2);
+               statsFunc(data[(y+1)*w+x+1], 3);
+            }
         }
     }