diff --git a/include/aare/Cluster.hpp b/include/aare/Cluster.hpp
index cc102c4..46be10d 100644
--- a/include/aare/Cluster.hpp
+++ b/include/aare/Cluster.hpp
@@ -100,4 +100,20 @@ struct is_cluster<Cluster<T, X, Y, CoordType>> : std::true_type {}; // Cluster
 
 template <typename T> constexpr bool is_cluster_v = is_cluster<T>::value;
 
+template <typename ClusterType,
+          typename = std::enable_if_t<is_cluster_v<ClusterType>>>
+struct extract_template_arguments; // Forward declaration
+
+// helper struct to extract template argument
+template <typename T, uint8_t ClusterSizeX, uint8_t ClusterSizeY,
+          typename CoordType>
+struct extract_template_arguments<
+    Cluster<T, ClusterSizeX, ClusterSizeY, CoordType>> {
+
+    using type = T;
+    static constexpr int cluster_size_x = ClusterSizeX;
+    static constexpr int cluster_size_y = ClusterSizeY;
+    using coordtype = CoordType;
+};
+
 } // namespace aare
diff --git a/include/aare/ClusterFile.hpp b/include/aare/ClusterFile.hpp
index eb6cc86..bc0ebd1 100644
--- a/include/aare/ClusterFile.hpp
+++ b/include/aare/ClusterFile.hpp
@@ -429,16 +429,24 @@ bool ClusterFile<ClusterType, Enable>::is_selected(ClusterType &cl) {
             return false;
         }
     }
-    // TODO types are wrong generalize
+
+    auto cluster_size_x = extract_template_arguments<
+        std::remove_reference_t<decltype(cl)>>::cluster_size_x;
+    auto cluster_size_y = extract_template_arguments<
+        std::remove_reference_t<decltype(cl)>>::cluster_size_y;
+
+    size_t cluster_center_index =
+        (cluster_size_x / 2) + (cluster_size_y / 2) * cluster_size_x;
+
     if (m_noise_map) {
-        int32_t sum_1x1 = cl.data[4]; // central pixel
-        int32_t sum_2x2 =
-            cl.max_sum_2x2().first; // highest sum of 2x2 subclusters
-        int32_t sum_3x3 = cl.sum(); // sum of all pixels
+        auto sum_1x1 = cl.data[cluster_center_index]; // central pixel
+        auto sum_2x2 = cl.max_sum_2x2().first; // highest sum of 2x2 subclusters
+        auto total_sum = cl.sum();             // sum of all pixels
 
         auto noise =
             (*m_noise_map)(cl.y, cl.x); // TODO! check if this is correct
-        if (sum_1x1 <= noise || sum_2x2 <= 2 * noise || sum_3x3 <= 3 * noise) {
+        if (sum_1x1 <= noise || sum_2x2 <= 2 * noise ||
+            total_sum <= 3 * noise) {
             return false;
         }
     }
diff --git a/src/ClusterVector.test.cpp b/src/ClusterVector.test.cpp
index c354891..c6a36d8 100644
--- a/src/ClusterVector.test.cpp
+++ b/src/ClusterVector.test.cpp
@@ -187,8 +187,8 @@ TEST_CASE("Concatenate two cluster vectors where we need to allocate",
 }
 
 struct ClusterTestData {
-    int8_t ClusterSizeX;
-    int8_t ClusterSizeY;
+    uint8_t ClusterSizeX;
+    uint8_t ClusterSizeY;
     std::vector<int64_t> index_map_x;
     std::vector<int64_t> index_map_y;
 };
@@ -213,8 +213,8 @@ TEST_CASE("Gain Map Calculation Index Map", "[.ClusterVector][.gain_map]") {
                         {-2, -2, -2, -2, -2, -1, -1, -1, -1, -1, 0, 0, 0,
                          0,  0,  1,  1,  1,  1,  1,  2,  2,  2,  2, 2}});
 
-    int8_t ClusterSizeX = clustertestdata.ClusterSizeX;
-    int8_t ClusterSizeY = clustertestdata.ClusterSizeY;
+    uint8_t ClusterSizeX = clustertestdata.ClusterSizeX;
+    uint8_t ClusterSizeY = clustertestdata.ClusterSizeY;
 
     std::vector<int64_t> index_map_x(ClusterSizeX * ClusterSizeY);
     std::vector<int64_t> index_map_y(ClusterSizeX * ClusterSizeY);