diff --git a/openbr/core/common.cpp b/openbr/core/common.cpp
index bfd38fb..d6c445a 100644
--- a/openbr/core/common.cpp
+++ b/openbr/core/common.cpp
@@ -76,3 +76,11 @@ QList<float> Common::linspace(float start, float stop, int n) {
     spaced.append(stop);
     return spaced;
 }
+
+QList<int> Common::ind2sub(int dims, int nPerDim, int idx) {
+    QList<int> subIndices;
+    for (int j = 0; j < dims; j++) {
+        subIndices.append(((int)floor( idx / pow((float)nPerDim, j))) % nPerDim);
+    }
+    return subIndices;
+}
diff --git a/openbr/core/common.h b/openbr/core/common.h
index 15516d0..09c171e 100644
--- a/openbr/core/common.h
+++ b/openbr/core/common.h
@@ -335,6 +335,10 @@ V<T> Downsample(V<T> vals, int k)
     return newVals;
 }
 
+/*! \brief Converts index into subdimensions.
+*/
+QList<int> ind2sub(int dims, int nPerDim, int idx);
+
 }
 
 #endif // COMMON_COMMON_H