diff --git a/openbr/plugins/quality.cpp b/openbr/plugins/quality.cpp
index 0e7bc66..0a02f40 100644
--- a/openbr/plugins/quality.cpp
+++ b/openbr/plugins/quality.cpp
@@ -184,10 +184,19 @@ class MatchProbabilityDistance : public Distance
 
     float compare(const cv::Mat &target, const cv::Mat &query) const
     {
-        const float rawScore = distance->compare(target, query);
-        if (rawScore == -std::numeric_limits<float>::max()) return rawScore;
-        if (!Globals->scoreNormalization) return -log(rawScore+1);
-        return mp(rawScore, gaussian);
+        return normalize(distance->compare(target, query));
+    }
+
+    float compare(const uchar *a, const uchar *b, size_t size) const
+    {
+        return normalize(distance->compare(a, b, size));
+    }
+
+    float normalize(float score) const
+    {
+        if (score == -std::numeric_limits<float>::max()) return score;
+        if (!Globals->scoreNormalization) return -log(score+1);
+        return mp(score, gaussian);
     }
 
     void store(QDataStream &stream) const